Inhalation of Nitric Oxide for Treating Respiratory Diseases

ABSTRACT

A method of treating a human subject which is effected by intermittent inhalation of gaseous nitric oxide at a concentration of at least 160 ppm is disclosed. The method can be utilized for treating a human subject suffering from, or prone to suffer from, a disease or disorder that is manifested in the respiratory tract, or from a disease or disorder that can be treated via the respiratory tract. The disclosed method can be effected while monitoring one or more of on-site and off-site parameters such as vital signs, methemoglobin levels, pulmonary function parameters, blood chemistry and hematological parameters, blood coagulation parameters, inflammatory marker levels, liver and kidney function parameters and vascular endothelial activation parameters, such that no substantial deviation from a baseline in seen in one or more of the monitored parameters.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/382,815, filed on Sep. 4, 2014, which is a National Phase of PCTApplication No. PCT/IL2013/050215 having International filing date ofMar. 7, 2013, which claims the benefit of priority under 35 USC § 119(e)of U.S. Provisional Patent Application No. 61/607,686 filed on Mar. 7,2012. The contents of the above applications are all incorporated byreference as if fully set forth herein in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to therapy,and more particularly, but not exclusively, to methods and devices fortreating respiratory diseases by inhalation of gaseous nitric oxide.

Nitric oxide (NO) is a small lipophilic signaling molecule with a smallstokes radius and a molecular weight of 30 grams/mol that enables it tocross the glycolipid cell plasma membrane into the cytosol readily andrapidly. NO has an unpaired electron available in its outer orbit thatcharacterizes it as a free radical. NO has been shown to play a criticalrole in various bodily functions, including the vasodilatation of smoothmuscle, neurotransmission, regulation of wound healing and immuneresponses to infections such as caused by bactericidal action directedtoward various organisms. NO has been demonstrated to play an importantrole in wound healing through vasodilatation, angiogenesis,anti-inflammatory and antimicrobial action.

NO is a common air pollutant and is present in concentrations of 150-650ppm in cigarette smoke and up to 1200 ppm in cigar and pipe smoke. TheNational Institute for Occupational Safety and Health (OSHA) and theEnvironmental Protection Agency have given an inhalation threshold limitvalue (TL V) as a time-weighted average (TWA) of 25 ppm for NO. TheTLV-TWA is the concentration to which a person's respiratory system maybe exposed continuously throughout a normal work week without adverseeffects and, when represented in ppm hours units, is calculated to be200 ppm hours. This level is a time-weighted average, that is, theaverage level of NO should be less than 25 ppm; however, brief exposuresto higher concentrations are allowed.

NO is produced by the innate immune response in organs and cells exposedto bacterial and viral infections. These include, among others, thenasopharyngeal airway, lungs and circulating neutrophils andmacrophages. NO is also a highly reactive microbicidal free radical thatpossesses antimicrobial activity against broad range of bacteria,parasites, fungi and viruses. The pore diameter in the cell walls of themicroorganisms through which the NO molecule must pass to affect thesepathogens is approximately five times wider so that there are fewbarriers to NO cell penetration. NO is therefore an essential part ofthe innate immune response. In addition, NO is one of the smallest, yetone of the most important, biological signaling molecules in mammals.

Other than being a well-established direct antimicrobial agent, it hasbeen hypothesized that the antimicrobial and cellular messengerregulatory properties of NO, delivered in an exogenous gaseous form,might easily enter the pulmonary milieu and be useful in optimizing thetreatment of uncontrolled pulmonary disease with specific actionsdirected at reducing bacterial burden, reducing inflammation andimproving clinical symptoms.

Some respiratory disorders and physiological conditions can be treatedby inhalation of gaseous nitric oxide (gNO). The use of gNO byinhalation can prevent, reverse, or limit the progression of disorderssuch as acute pulmonary vasoconstriction, traumatic injury, aspirationor inhalation injury, fat embolism in the lung, acidosis, inflammationof the lung, adult respiratory distress syndrome, acute pulmonary edema,acute mountain sickness, post cardiac surgery, acute pulmonaryhypertension, persistent pulmonary hypertension of a newborn, perinatalaspiration syndrome, haline membrane disease, acute pulmonarythromboembolism, heparin-protamine reactions, sepsis, asthma and statusasthmaticus or hypoxia. Inhaled gNO can also be used to treat cysticfibrosis (CF), chronic pulmonary hypertension, bronchopulmonarydysplasia, chronic pulmonary thromboembolism and idiopathic or primarypulmonary hypertension or chronic hypoxia.

From the toxicological aspect, NO has a half-life in the body of lessthan 6 seconds and a radius of action of approximately 200 microns fromits site of origin, beyond which it is inactivated through binding tosulfhydryl groups of cellular thiols or by nitrosylation of the hememoieties of hemoglobin to form methemoglobin (MetHb). MetHb reductasereduces NO to nitrates in the blood serum. Nitrate has been identifiedas the predominant nitric oxide metabolite excreted in the urine,accounting for more than 70% of the nitric oxide dose inhaled. Nitrateis cleared from the plasma by the kidney at rates approaching the rateof glomerular filtration. Blood levels of MetHb in healthy humans aretypically less than 2%. Potential side effects of high dose NO treatmenthence include the binding of NO to hemoglobin and the formation ofMetHb, which could lead to decreased oxygen transport, and the capacityof NO to act as a nitrosylating agent on proteins and other cellconstituents. Formation of MetHb and increased levels thereof have beenobserved in previous studies of gNO inhalation by healthy humanindividuals, wherein inhalation of gNO at 128 ppm for 3 hours and at 512ppm for 55 minutes has been reported to drive the levels of MetHb overthe safe threshold of 5% [Borgese N. et al., J. Clin. Invest., 1987, 80,1296-1302; Young J. D. et al., Intensive Care Med., 1994, 20, 581-4 andYoung J. D. et al., Brit. J. Anaesthesia, 1996, 76, 652-656].

Thus, concerns have been raised regarding the potential use of NO as atherapeutic agent in various clinical scenarios. To date, studiesindicate that acute pulmonary injury, pulmonary edema, hemorrhage,changes in surface tension of surfactant, reduced alveolar numbers andairway responsiveness may be caused by high airway levels of NO, NO₂ andother oxides of nitrogen [Hurford W., Resp. Care, 2005, 50, 1428-9].

Several animal studies conducted in order to evaluate the safety windowfor gNO exposure were reported on the Primary Medical Review of NDA20-845 (INOmax nitric oxide gas). Included in these reports is the studyreferred to as RDR-0087-DS, wherein groups of 10 rats each were exposedto room air or to 80, 200, 300, 400 or 500 ppm gNO for 6 continuoushours per day for up to 7 days. It is reported that all of the animalsdied on the first day of exposure to 400 and 500 ppm gNO with MetHblevels of 72.5 and 67 percents respectively. Six of the animals treatedwith 300 ppm gNO died during the first 1-2 days. All deaths wereattributed to methemoglobinemia.

In additional studies, rats were exposed continuously to room air, 40,80, 160, 200 and 250 ppm gNO for 6 hours/day for 28 days. No deathsoccurred at gNO concentrations below 200 ppm.

At present, inhalation of gaseous nitric oxide (gNO) as a selective,short acting vasodilator is approved only at 80 ppm for use in full terminfants with hypoxic respiratory failure associated with pulmonaryhypertension. However, other studies have shown that at such lowconcentration of inhaled gNO, treatment of adults' respiratory diseasesis limited, and the use of higher doses of gNO for treating variousmedical conditions by inhalation requires in-depth safety studies inhumans.

Miller et. al. reported the effect of 1,600 ppm hours gNO against fiveplanktonic (suspended in a liquid) species of methicillin resistant S.aureus (MRSA). An in vitro biofilm MRSA model was also used to comparegNO to the antibiotic vancomycin as an antibacterial agent. For thebiofilm experiment, a drip flow reactor was used to grow a MRSA biofilmwhich was then exposed for eight hours to Ringers lactate, 200 ppm gNO(1,600 ppm hours), air or vancomycin (100-times MIC level). A reductionin the population of all five MRSA planktonic strains was observed afterexposure to 1,600 ppm hours of gNO. In the biofilm experiment gNO wasalso shown to reduce MRSA.

Additional animal studies have shown that gNO at 160-200 ppm can exertpotent antimicrobial effects against a broad range of microbes in vitro,ex vivo and in animal models [Kelly T. J. et al., J. Clin. Invest.,1998, 102, 1200-7; McMullin B. et al., Resp. Care., 2005, 50, 1451-6;Ghaffari A. et al., Nitric Oxide, 2005, 12, 129-40; Ghaffari A. et al.,Wound Repair Regen., 2007, 15, 368-77; Miller C. C. et al., J. Cutan.Med. Surg. 2004, 8, 233-8; Miller C. C. et al., Nitric Oxide, 2009, 20,16-23], further suggesting its use as an antimicrobial agent inappropriate concentrations.

Studies conducted in a rat model of Pseudomonas aeruginosa pneumoniatested the antimicrobial effect of a gNO inhaled delivery regimen ofintermittent 30 minute exposures of 160-200 ppm gNO, and revealed that160 ppm gNO in that regiment is effective to reduce the pulmonarybioburden and leukocyte infiltration [Hergott C. A. et al., Am. J. Resp.Crit. Care Med., 2006, 173, A135]. This treatment was also shown todecrease the clinical symptoms of bovine respiratory disease in cattle[Schaefer A. L. et al., Online J. Vet. Res., 2006, 10, 7-16].

Miller, C. C. et al. [J. Cutan. Med. Surg., 2004, 8(4), 233-8] reportedon topical treatment of a subject who had a chronic, non-healing woundand presence of a reoccurring biofilm with gNO at a treatmentconcentration of 200 ppm for two weeks. Within the first three days oftreatment, the subject's biofilm was no longer visibly present and atone week, the wound size was reduced by 42%. The subject's ulcercontinued to heal following the cessation of nitric oxide exposure.

WO 2005/110441 teaches a method and a corresponding device for combatingmicrobes and infections by delivering intermittent high doses of 160-400ppm gNO to a mammal for a period of time which cycles between high andlow concentration of nitric oxide gas. The regimen involves delivery of160 ppm gNO for 30 minutes every four hours with 0-20 ppm delivered forthe 3.5 hours between the higher concentration deliveries. Noexperimental data are presented in this publication.

U.S. Pat. No. 7,122,018 teaches topical intermittent exposure to highconcentration of nitric oxide ranging 160-400 ppm, for treatment ofinfected wounds and respiratory infections by a regimen of 4-hoursessions interrupted by 1 hour of rest while monitored methemoglobinblood levels.

U.S. Pat. No. 7,516,742 teaches intermittent high-low dosing byinhalation of gNO to overcome gNO-related toxicity, wherein the highconcentration of gNO ranges from 80 to 300 ppm and the low concentrationranges from 0 to 80 ppm, while the regimen may be 160 ppm for 30 minutesevery four hours with 20 ppm delivered for the 3.5 hours between thehigher concentration deliveries while monitoring the concentration ofO₂, NO and NO₂.

U.S. Pat. No. 7,520,866 teaches topical exposure of wounds to gNO at ahigh concentration ranging 160-400 ppm with a regime of two 4-hoursessions, interrupted by 1 hour of rest, wherein after a first treatmentperiod with high concentration of gNO, a second treatment period at alower concentration of 5-20 ppm may be provided to restore the balanceof nitric oxide and induce collagen expression to aid in the closure ofthe wound.

U.S. Pat. No. 7,955,294 teaches a method and a corresponding device fortopical and inhaled intermittent delivery high-low doses of gNO for aperiod of time which cycles between high and low concentration, with anexemplary cycle regimen of 160-200 ppm for 30 minutes followed by 0-80ppm 3.5 hours wherein the cycling regimen can span 1-3 days.

Additional background art includes U.S. Pat. Nos. 8,083,997, 8,079,998,8,066,904, 8,057,742, 7,531,133, 6,432,077, U.S. Patent Application Nos.2011/0262335, 2011/0259325, 2011/0240019, 2011/0220103 and 2010/0331405,2011/0112468, 2008/028786, 2007/0116785, 2007/0088316, 2007/0065473,2007/0014688, 2006/0207594, 2005/0191372 and WO 2006/071957, WO2006/110923, WO 2006/110923, WO 2007/057763, WO 2007/057763, WO2000/30659 and EP 0692984; Miller C. C. et al., Antimicrobial Agents AndChemotherapy, 2007, 51(9), 3364-3366; and Miller C. C. et al., [RespCare, 2008, 53(11), 1530].

SUMMARY OF THE INVENTION

The present inventors have studied the effect of intermittent inhalationof gaseous nitric oxide at a concentration of 160 ppm or more by humansubjects and have shown that such intermittent inhalation protocol donot result in substantial changes in various physiological parameters ofthe human subject. Exemplary such parameters are those obtainableon-site in real-time, such as methemoglobin level, end-tidal CO₂ level,and oxygenation, and parameters which are obtainable off-site in thelaboratory, such as blood nitrite level, urine nitrite level, andinflammatory markers' level. The present inventors have thereforedemonstrated that such a method can be effected safely. Embodiments ofthe present invention therefore relate to methods of administeringgaseous nitric oxide to human subjects in need thereof, while theseparameters remain substantially unchanged. The disclosed administrationcan be used in methods of treating and/or preventing various medicalconditions, which are manifested in the respiratory tract, or which canbe treated via the respiratory tract, by subjecting a human subject tointermittent inhalation of gaseous nitric oxide at a concentration of160 ppm or more.

According to an aspect of some embodiments of the present inventionthere is provided a method of treating a human subject suffering from adisease or disorder that is manifested in the respiratory tract or adisease or disorder that can be treated via the respiratory tract, themethod comprising subjecting the subject to intermittent inhalation ofgNO at a concentration of at least 160 ppm, thereby treating the diseaseor disorder.

According to some embodiments of the present invention, the disease ordisorder is selected from the group consisting of a bacterial-, viral-and/or fungal bronchiolitis, a bacterial-, viral- and/or fungalpharyngitis and/or laryngotracheitis, a bacterial-, viral- and/or fungalpneumonia, a bacterial-, viral- and/or fungal sinusitis, a bacterial-,viral- and/or fungal upper and/or lower respiratory tract infection, abacterial-, viral- and/or fungal-exacerbated asthma, a bacterial-,viral- and/or fungal conjunctivitis and uveitis, a respiratory syncytialviral infection, bronchiectasis, bronchitis, chronic obstructive lungdisease (COPD), cystic fibrosis (CF), emphysema, otitis, otitis externa,otitis media, primary ciliary dyskinesia (PCD), aspergillosis,aspergilloma, pulmonary aspergillosis (ABPA) and cryptococcosis.

According to some embodiments of the present invention, the disease ordisorder is an ophthalmological, otolaryngological and/or upperrespiratory tract disease or disorder.

According to some embodiments of the present invention, theophthalmological, otolaryngological and/or upper respiratory tractdisease and disorder involves an infection or an inflammation of abodily site selected from the group consisting of an ear cavity, a nasalcavity, an eye, a sinus cavity, an oral cavity, a pharynx, a epiglottis,a vocal cord, a trachea, an apex and an upper esophagus.

According to some embodiments of the present invention, theotolaryngological and/or upper respiratory tract disease and disorder isselected from the group consisting of a common cold, a stomatognathicdisease, amigdalitis, an oral fugal infection, bacterial-, viral- and/orfungal sinusitis, bronchitis, candidiasis of the oral cavity (thrush),canker sores, epiglottitis (supraglottitis), halitosis, herpes,laryngitis, laryngotracheitis, nasopharyngitis, otitis, otitis externa,otitis media, conjunctivitis, uveitis, pharyngitis, rhinitis,rhinopharyingitis, rhinosinusitis, stomatitis, tonsillitis, tracheitis,tracheitis and tympanitis.

According to some embodiments of the present invention, the disease ordisorder is a disease or disorder of the lower respiratory system of ahuman subject.

According to some embodiments of the present invention, the disease ordisorder is selected from the group consisting of an obstructivecondition, a restrictive condition, a vascular disease and an infection,an inflammation due to inhalation of foreign matter and an inhaledparticle poisoning.

According to some embodiments of the present invention, the obstructivecondition selected from the group consisting of a chronic obstructivelung disease (COPD), emphysema, bronchiolitis, bronchitis, asthma andviral, bacterial and fungal exacerbated asthma; the restrictivecondition selected from the group consisting of fibrosis, cysticfibrosis, sarcoidosis, alveolar damage and pleural effusion; thevascular disease selected from the group consisting of pulmonary edema,pulmonary embolism and pulmonary hypertension; the infection selectedfrom the group consisting of respiratory syncytial virus infection,tuberculosis, viral-, bacterial-, fungal-, and/or parasitic pneumonia,idiopathic pneumonia; and the inflammation due to inhalation of foreignmatter and an inhaled particle poisoning selected from the groupconsisting of smoke inhalation, asbestosis and exposure to particulatepollutants and fumes.

According to some embodiments of the present invention, the disease ordisorder is bronchiolitis.

According to some embodiments of the present invention, thebronchiolitis is associated with a virus.

According to some embodiments of the present invention, the virus isselected from the group consisting of a respiratory syncytial virus(RSV), a rhinovirus, a coronavirus, an enterovirus, an influenza Aand/or B virus, a parainfluenza 1, 2 and/or 3 virus, a bocavirus, ahuman metapneumovirus, SARS and an adenovirus.

According to some embodiments of the present invention, the disease ordisorder is asthma.

According to some embodiments of the present invention, the disease ordisorder is cystic fibrosis.

According to some embodiments of the present invention, the disease ordisorder is associated with an influenza virus.

According to some embodiments of the present invention, the disease ordisorder is COPD.

According to some embodiments of the present invention, the disease ordisorder selected from the group consisting of an acute respiratorydisease or disorder, a chronic respiratory disease or disorder, anobstructive respiratory disease or disorder, an intrinsic or extrinsicrestrictive respiratory disease or disorder, a pulmonary vasculardisease or disorder, an infectious respiratory disease or disorder, aninflammatory respiratory disease or disorder, a pleural cavity diseaseor disorder, and a neonatal respiratory disease or disorder.

According to some embodiments of the present invention, the disease ordisorder is associated with a pathogenic microorganism.

According to some embodiments of the present invention, the pathogenicmicroorganism is selected from the group consisting of a Gram-negativebacterium, a Gram-positive bacterium, a virus, a fungus and a parasite.

According to some embodiments of the present invention, the disease ordisorder is selected from the group consisting of a bacterial-, viral-and/or fungal bronchiolitis, a bacterial-, viral- and/or fungalpharyngitis and/or laryngotracheitis, a bacterial-, viral- and/or fungalsinusitis, a bacterial-, viral- and/or fungal upper and/or lowerrespiratory tract infection, a bacterial-, viral- and/orfungal-exacerbated asthma, a bacterial-, viral-, fungal- and/orparasitic pneumonia, a common cold, a cystic fibrosis related infection,a respiratory syncytial viral infection, acidosis or sepsis, an oralfugal infection, aspergillosis, aspergilloma, cryptococcosis, pulmonaryaspergillosis (ABPA), cryptococcosis bronchitis, candidiasis of the oralcavity (thrush), canker sores, epiglottitis (supraglottitis), halitosis,herpes, laryngitis, laryngotracheitis, nasopharyngitis, otitis andotitis media, pharyngitis, respiratory syncytial virus infection, abacterial-, viral- and/or fungal conjunctivitis and uveitis, rhinitis,rhinopharyingitis, rhinosinusitis, stomatitis, tonsillitis, tracheitis,tuberculosis and tympanitis.

According to some embodiments of the present invention, the methodfurther comprises, or is effected while, monitoring, during andfollowing the subjecting, at least one on-site parameter selected fromthe group consisting of:

-   -   a methemoglobin level (SpMet);    -   an oxygen saturation level (SpO₂);    -   an end tidal CO₂ level (ETCO₂); and

a fraction of inspired oxygen level (FiO₂),

and/or at least one off-site parameter selected from the groupconsisting of:

a serum nitrite level (NO₂ ⁻); and

an inflammatory cytokine plasma level,

in the subject, as these parameters are described herein.

According to some embodiments of the present invention, the methodfurther comprises, or is effected while, monitoring, at least two of theparameters, as described herein.

According to some embodiments of the present invention, the methodfurther comprises, or is effected while, monitoring all of theparameters.

According to some embodiments of the present invention, a change in theat least one of the parameters following the subjecting is less than 2acceptable deviation units from a baseline, as described herein.

According to some embodiments of the present invention, a change in atleast two of the parameters following the subjecting is less than 2acceptable deviation units from a baseline.

According to some embodiments of the present invention, a change in allof the parameters following the subjecting is less than 2 acceptabledeviation units from a baseline.

According to some embodiments of the present invention, a change in atleast one of the on-site parameters following the subjecting is lessthan 2 acceptable deviation units from a baseline.

According to some embodiments of the present invention, a change in atleast one of the off-site parameters following the subjecting is lessthan 2 acceptable deviation units from a baseline.

According to some of any of the embodiments of the present invention,the method further comprises, or is effected while, monitoring urinenitrite level in the subject, as described herein.

According to some embodiments of the present invention, the methodfurther comprises, or is effected while, monitoring a change in theurine nitrite level following the subjecting is less than 2 acceptabledeviation units from a baseline.

According to some of any of the embodiments of the present invention,the method further comprises, or is effected while, monitoring in thesubject at least one off-site parameter selected from the groupconsisting of:

a hematological marker;

a vascular endothelial activation factor;

a coagulation parameter;

a serum creatinine level; and

a liver function marker, as these parameters are described herein, inthe subject.

According to some embodiments of the present invention, a change in atleast one of the off-site parameters following the subjecting is lessthan 2 acceptable deviation units from a baseline.

According to some of any of the embodiments of the present invention,the method further comprises, or is effected while, monitoring at leastone off-site parameter selected from the group consisting of:

a hematological marker;

a vascular endothelial activation factor;

a coagulation parameter;

a serum creatinine level; and

a liver function marker, in the subject, as these parameters aredescribed herein.

According to some embodiments of the present invention, a change in theat least one parameter following the subjecting is less than 2acceptable deviation units from a baseline.

According to some of any of the embodiments of the present invention,the method further comprises, or is effected while, monitoring in thesubject at least one on-site parameter selected from the groupconsisting of:

a vital sign; and

a pulmonary function, as these parameters are described herein.

According to some embodiments of the present invention, no deteriorationis observed in the at least one parameter during and following thesubjecting.

According to some of any of the embodiments of the present invention,the intermittent inhalation comprises at least one cycle of continuousinhalation of the gNO for a first time period, followed by inhalation ofno gNO for a second time period.

According to some embodiments of the present invention, the first timeperiod is about 30 minutes.

According to some embodiments of the present invention, the second timeperiod ranges from 3 to 5 hours.

According to some embodiments of the present invention, the inhalationcomprises from 1 to 6 of the cycles per day.

According to some embodiments of the present invention, the inhalationcomprises 5 of the cycles per day.

According to some embodiments of the present invention, during the firsttime period, the concentration of gNO in the mixture deviates from theconcentration of at least 160 ppm by less than 10%.

According to some embodiments of the present invention, during the firsttime period, a concentration of NO₂ in the mixture is less than 5 ppm.

According to some embodiments of the present invention, during the firsttime period, a concentration of O₂ in the mixture ranges from 20% to25%.

According to some embodiments of the present invention, during the firsttime period, a fraction of inspired oxygen level (FiO₂) in the mixtureranges from 21% to 100%.

According to some embodiments of the present invention, the at least oneparameter comprises ETCO₂ and during and following the subjecting, theETCO₂ is less than 60 mmHg.

According to some embodiments of the present invention, the at least oneparameter comprises SpMet and during and following the subjecting, theSpMet is increased by less than 5%.

According to some embodiments of the present invention, the at least oneparameter comprises SpO₂ and during the subjecting, a level of the SpO₂is higher than 89%.

According to some embodiments of the present invention, the at least oneparameter comprises serum nitrite/nitrate level and during and followingthe subjecting, a level of the serum nitrite is less than 2.5/25micromole per liter respectively.

According to some of any of the embodiments described herein, theintermittent inhalation of gNO is effected during a time period thatranges from 1 to 7 days.

According to some of any of the embodiments described herein, thesubjecting is effected by an inhalation device selected from the groupconsisting of stationary inhalation device, a portable inhaler, ametered-dose inhaler, an atmospherically controlled enclosure and anintubated inhaler.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention pertains. Although methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, exemplarymethods and/or materials are described below. In case of conflict, thepatent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and are notintended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, it is stressed that theparticulars shown are by way of example and for purposes of illustrativediscussion of embodiments of the invention. In this regard, thedescription taken with the drawings makes apparent to those skilled inthe art how embodiments of the invention may be practiced.

In the drawings:

FIGS. 1A-B present background art bar graphs showing the gNO dosagecurve as measured for S. aureus (FIG. 1A) and P. aeruginosa (FIG. 1B)grown on solid media, wherein relative percentage of growth of colonyforming units (CFU) at 50, 80, 120 and 160 parts per million (ppm) ofgaseous nitric oxide (gNO) compared with growth of CFU in medical air(100%);

FIGS. 2A-C present background art comparative plots showing the viralplaque formation in tissue as a function of time as measured forinfluenza A/victoria/H3N2 virions after exposure to nitric oxide 160 ppmand 800 ppm continuously for 4 hours (FIG. 2A), the same virions afterbeing exposed to one gNO dose over 30 minute as compared to three 30minute treatments Q4 h (FIG. 2B), and the effect of continuous exposureto gNO at a concentration of 160 ppm for 3 hours of the highlypathogenic Avian Influenza H7N3 (as presented in US 2007/0116785);

FIGS. 3A-D present images showing tissue culture samples harboring humanrgRSV30 a common viral lung virus and the causative agent ofBroncheolitis, coupled to a green fluorescent protein, and having astarting viral level of 2000 PFU (FIG. 3A), 1000 PFU (FIG. 3B) and 500PFU (FIG. 3C), upon exposure to 160 ppm gNO for 30 minutes, and acomparative bar plot presenting the plaque reduction in the testedsamples to control samples exposed to ambient air;

FIGS. 4A-B present of the data obtained while monitoring methemoglobin(MetHb) levels before, during and after inhalation of 160 ppm of gaseousnitric oxide by 10 healthy human individuals, undergone 5 courses of gNOadministration by inhalation daily, each lasting 30 minutes, for 5consecutive days, while methemoglobin levels were measured using a pulseoximeter, wherein FIG. 4A is a plot of methemoglobin levels by percentsas a function of time as measured before (time point 0), during 250individual 30 minutes gNO administration courses (time interval of 0 to30 minutes), after the courses (time interval of 30 to 60 minutes) andat 120 minutes, 180 minutes and 240 minutes after gNO administration wasdiscontinued, and FIG. 4B is a plot of methemoglobin levels by percentsas a function of time as measured at the beginning and end of 30 minutesgNO administration courses given over the course of 5 days, and followed8, 12 and 26 days after gNO administration was discontinued;

FIGS. 5A-F present the data obtained while monitoring pulmonary functionbefore, during and after inhalation of 160 ppm of gaseous nitric oxideby 10 healthy human individuals, wherein baseline values of pulmonaryfunction tests were obtained within 7 days prior to gNO administration,and values during gNO administration were obtained on day 2 of the5-days treatment and other data were obtained after the final gNOadministration on day 5 and on days 8, 12 and 26, wherein FIG. 5Apresents forced expiratory volume in 1 second (FEV1) in percents (FEV₁),FIG. 5B presents maximum mid-expiratory flow (MMEF), FIG. 5C presentscarbon monoxide diffusing capacity (DLCO), FIG. 5D presents forced vitalcapacity (FVC), FIG. 5E presents total lung capacity (TLC) and FIG. 5Fpresents residual volume (RV), while all data are presented as means ofall ten subjects and absolute differences compared to baseline prior togNO administration, and statistical differences were assessed byMann-Whitney test;

FIGS. 6A-F present blood levels of various cytokines before and afterinhalation of 160 ppm gaseous nitric oxide by 10 healthy humanindividuals, as measured from blood samples collected within 7 daysprior to gNO administration, each day during the treatment and 8, 12 and26 days thereafter, wherein FIG. 6A presents the plasma levels of tumornecrosis factor (TNF)α, interleukin (IL)-1ß data is presented in FIG.6B, IL-6 in FIG. 6C, IL-8 in FIG. 6D, IL-10 in FIG. 6E and IL-12p70 inFIG. 6F, as determined by a cytometric bead array while statisticaldifferences are compared by repeated measures ANOVA with Bonferroni posttest for parametric data (IL-6, IL-8, IL-10, IL-12p70), or Friedman testwith Dunn's post test for non-parametric data (TNF and IL-1b); and

FIGS. 7A-C present plasma levels of angiopoietin (Ang)-1 and Ang-2before and after inhalation of 160 ppm gaseous nitric oxide by 10healthy human individuals, as measured in blood sample collected within7 days prior to gNO inhalation, each day during gNO administration and8, 12 and 26 days thereafter, wherein plasma levels of Ang 1 are shownin FIG. 7A, Ang-2 in FIG. 7B, and Ang-2/Ang-1 ratios in FIG. 7C, asdetermined by using a cytometric bead array while statisticaldifferences were assessed compared by Friedman test with Dunn's posttest.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to medicaltreatment of respiratory diseases in human subjects, and moreparticularly, but not exclusively, to medical procedures based oninhalation of gaseous nitric oxide and devices for effecting the same.

The principles and operation of the present invention may be betterunderstood with reference to the figures and accompanying descriptions.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details set forth in the following description or exemplified bythe Examples. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

As discussed hereinabove, inhalation of gaseous nitric oxide (gNO) hasbeen shown to be a highly effective broad-spectrum antimicrobialtherapy; however, at effective antimicrobial concentration gNO maypresent serious adverse effects on humans. As shown in previous studies,the currently approved dose of 80 ppm gNO is presumably too low to exertsufficient antimicrobial effects.

As further discussed hereinabove, intermittent dosing and delivery byinhalation of gNO, cycling between high concentrations of gNO for arelatively short period of time and longer periods of no or lowconcentration of gNO has been suggested for overcoming the problems ofNO toxicity. It has been suggested that the high concentration of gNO,delivered according to an intermittent regimen, would be effective inoverwhelming the nitric oxide defense mechanisms of pathogens.

It has been further suggested in the art that the high concentration ofgNO may be delivered at a concentration of between 80 ppm to 300 ppm,and that the time periods for delivering the high concentration shouldafford a daily delivery of 600 to 1000 ppm hours.

However, to date, a regimen of intermittent inhalation of gNO, cyclingbetween high concentrations of gNO for a relatively short period of timeand longer periods of no or low concentration of gNO has not beenapplied on humans. Studies demonstrating safety and efficacy of suchprotocols have never been conducted in human subjects and no protocolswere provided for monitoring safety parameters and/or for treating humanpatients in need of gNO inhalation above the approved dose of 80 ppm.

In the course of devising and practicing novel methods of treatingvarious bacterial, viral and protozoal infections, the present inventorshave conducted studies in human subjects, and compiled suitableprotocols for safe and effective treatment of a human subject byintermittent inhalation of high concentrations of gNO. The presentinventors have demonstrated that short durations of high concentrationsof gNO do not cause lung injury or other signs of adverse effects inhumans and even improve some vital effects such as lung function andheart rate.

Specifically, the present inventors have conducted a prospective phase Iopen label safety study in healthy adults, who inhaled 160 ppm gNO for30 minutes, five times a day, for five consecutive days. Neithersignificant adverse events nor adverse events attributable to gNOinhalation occurred and all individuals tolerated the gNO treatmentcourses well. Forced expiratory volume in 1 sec (FEV₁) percentage andother lung function parameters were improved and serumnitrites/nitrates, prothrombin, pro-inflammatory cytokine and chemokinelevels, did not differ between baseline and day 5, while methemoglobinlevels increased during the study period to a tolerated and acceptedlevel of 0.9%. It was thus demonstrated that inhalation of 160 ppm gNOor more for 30 minutes, about 5 times daily, for 2-7 consecutive days,is safe and well tolerated in healthy individuals.

The present invention, in some embodiments thereof, therefore providesmethods of treating human subjects by intermittent inhalation of highconcentration of gNO. In some embodiments, the methods disclosed hereinare effected while monitoring various parameters relevant formaintaining the desired dosage and regimen, relevant to the safety ofthe procedure and relevant for efficacy of the treatment.

According to an aspect of some embodiments of the present invention,there is provided a method of treating a human subject in need ofinhalation of gaseous NO (gNO), which is effected by subjecting thehuman subject to intermittent inhalation of gNO at a concentration of atleast 160 ppm.

In some embodiments, the method is effected while monitoring variousphysiological parameters in the subject, as described herein.

According to some embodiments of the invention, subjecting the humansubject to gNO intermittent inhalation is effected by intermittentlysubjecting the human subject to a gaseous mixture which contains gNO atthe indicated concentration (a gNO-containing gaseous mixture).

The human subject can be subjected to the inhalation by active orpassive means.

By “active means” it is meant that the gaseous mixture is administeredor delivered to the respiratory tract of the human subject. This caneffected, for example, by means of an inhalation device having adelivery interface adapted for human respiratory organs. For example,the delivery interface can be placed intermittently on the humansubject's respiratory organs, whereby when it is removed, the subjectbreaths ambient air or any other gaseous mixture that is devoid of gNO,as defined herein.

By “passive means” it is meant that the human subject inhales a gaseousmixture containing the indicated dose of gNO without devices fordelivering the gaseous mixture to the respiratory tract.

For example, the subject can be subjected to 160 ppm or more gNO in anintermittent regimen by entering and exiting an atmosphericallycontrolled enclosure filled with the gNO-containing mixture of gasesdiscussed herein, or by filling and evacuating an atmosphericallycontrolled enclosure which is in contact with a subject's respiratorytract.

The term “intermittent” is used herein and in the art as an antonym of“continuous”, and means starting and ceasing an action and/or performingan action in intervals.

By “intermittent inhalation” it is meant that the subject is subjectedto a gaseous mixture that contains the indicated concentration of gNOintermittently, and thus inhales such a gNO-containing gaseous mixturetwo or more times with intervals between each inhalation. The subjecttherefore inhales the gNO-containing gaseous mixture, then stopsinhaling a gNO-containing gaseous mixture and inhales instead a gaseousmixture that does not contain the indicated concentration of gNO (e.g.,air), then inhales again the gNO-containing gaseous mixture, and so onand so forth.

Hereinthroughout, “a gNO-containing gaseous mixture” is used, forsimplicity, to describe a gaseous mixture that contains at least 160 ppmgNO. The gNO-containing mixture can comprise 160 ppm, 170 ppm, 180 ppm,190 ppm, 200 ppm and even higher concentrations of gNO. Other gaseousmixtures mentioned herein include less than 160 ppm gNO or are beingessentially devoid of gNO, as defined herein.

By “essentially devoid of gNO” it is meant no more than 50 ppm, no morethan 40 ppm, no more than 30 ppm, no more than 20 ppm, no more than 10ppm, no more than 5 ppm, no more than 1 ppm and no more than ppb,including absolutely no gNO.

In some embodiments, the method is carried out while maintaining acontrolled mixture of inhaled and exhaled gases by standard means formonitoring and controlling, on-site, the contents and/or flow of themixture to which the subject is subjected to, or that which is deliveredthrough a delivery interface, and/or while monitoring on-site exhaledgases and controlling the intake by feedback in real-time. In someembodiments, the method is effected while monitoring the concentrationof gNO, FiO₂/O₂, ETCO₂, and NO₂ in the gaseous mixture to which thesubject is exposed or by monitoring other bodily systems non-invasively,such as blood oxygen saturation (SpO₂/SaO₂/DO) and the presence ofmethemoglobin in the blood (SpMet).

In some embodiments, the concentration of gNO in the gNO-containinggaseous mixture is controlled so as not to deviate from a predeterminedconcentration by more than 10%. For example, the method is carried outwhile the concentration of gNO, set to 160 ppm, does not exceed marginsof 144 ppm to 176 ppm.

Similarly, the NO₂ content in a gNO-containing gaseous mixture iscontrolled such that the concentration of NO₂ is maintained lower than 5ppm.

Further, oxygen level in the gNO-containing gaseous mixture iscontrolled such that the concentration of O₂ in the mixture ranges fromabout 20% to about 25%.

Alternatively or in addition, the oxygen level in the gNO-containinggaseous mixture is controlled such that the fraction of inspired oxygen(FiO₂) ranges from about 20% to about 100%.

The phrase “fraction of inspired oxygen” or “FiO₂”, as used herein,refers to the fraction or percentage of oxygen in a given gas sample.For example, ambient air at sea level includes 20.9% oxygen, which isequivalent to FiO₂ of 0.21. Oxygen-enriched air has a higher FiO₂ than0.21, up to 1.00, which means 100% oxygen. In the context of embodimentsof the present invention, FiO₂ is kept under 1 (less than 100% oxygen)

The phrase “end tidal CO₂” or “ETCO₂”, as used herein, refers to thepartial pressure or maximal concentration of carbon dioxide (CO₂) at theend of an exhaled breath, which is expressed as a percentage of CO₂ orthe pressure unit mmHg. Normal values for humans range from 5% to 6%CO₂, which is equivalent to 35-45 mmHg. Since CO₂ diffuses out of thelungs into the exhaled air, ETCO₂ values reflect cardiac output (CO) andpulmonary blood flow as the gas is transported by the venous system tothe right side of the heart and then pumped to the lungs by the rightventricles. A device called capnometer measures the partial pressure ormaximal concentration of CO₂ at the end of exhalation. In the context ofembodiments of the present invention, a capnometer is used and ETCO₂levels are monitored so as to afford a warning feedback when ETCO₂ ismore than 60 mmHg.

Levels of respiratory NO, NO₂ and O₂ concentration levels (both inhaledand exhaled; inspiratory and expiratory gases) are typically monitoredcontinuously by sampling from a mouthpiece sample port located in aninhalation mask NO, NO₂ and O₂ equipped with an electrochemicalanalyzer. In the context of embodiments of the present invention, safetyconsiderations requires the absolute minimization of the number ofoccasions in which NO₂ levels exceed 5 ppm, gNO concentration variationsexceeding 10%, and FiO₂/O₂ levels drop below 20% during gNOadministration.

According to some embodiments of the present invention, the intermittentinhalation includes one or more cycles, each cycle comprising continuousinhalation of a gaseous mixture containing gNO at the specified highconcentration (e.g., at least 160 ppm) for a first time period, followedby inhalation of a gaseous mixture containing no gNO for a second timeperiod. According to some embodiments of the present invention, duringthe second period of time the subject may inhale ambient air or acontrolled mixture of gases which is essentially devoid of gNO, asdefined herein.

In some embodiments, the first time period spans from 10 to 45 minutes,or from 20 to 45 minutes, or from 20 to 40 minutes, and according tosome embodiments, spans about 30 minutes.

According to some embodiments of the present invention, the second timeperiod ranges from 3 to 5 hours, or from 3 to 4 hours, and according tosome embodiments the second time period spans about 3.5 hours.

According to some embodiments of the present invention, this inhalationregimen is repeated 1-6 times over 24 hours, depending on the durationof the first and second time periods.

In some embodiments, a cycle of intermittent delivery of gNO, e.g., 160ppm for 30 minutes followed by 3.5 hours of breathing no gNO, isrepeated from 1 to 6 times a day. According to some embodiments, thecycles are repeated 5 times a day.

According to some embodiments of the present invention, the regimen of1-5 cycles per day is carried out for 1 to 7 days, or from 2 to 7 days,or from 3 to 7 days. According to some embodiments of the presentinvention, the intermittent inhalation is effected during a time periodof 5 days. However, longer time periods of intermittent gNOadministration as described herein, are also contemplated.

In some embodiments, the method is effected while monitoring one or morephysiological parameters in the subject and while assuring that nosubstantial change is effected in the monitored parameters (asdemonstrated herein).

In some embodiments, monitoring the one or more physiological parametersis effected by noninvasive measures and/or mild invasive measures.

In some embodiments, monitoring the physiological parameter(s) in thesubject is effected by on-site measurement and analysis techniques basedon samples collected sporadically, continuously or periodically from thesubject on-site in real-time at the subject's bed-side, and/or off-sitemeasurement and analysis techniques based on samples collectedsporadically or periodically from the subject which are sent forprocessing in a off-site which provides the results and analysis at alater point in time.

In the context of some embodiments of the present invention, the phrase“on-site measurement and analysis techniques” or “on-site techniques”,refers to monitoring techniques that inform the practitioner of a givenphysiological parameter of the subject in real-time, without the need tosend the sample or raw data to an off-site facility for analysis.On-site techniques are often noninvasive, however, some rely on samplingfrom an invasive medical device such as a respiratory tubus, a drainertube, an intravenous catheter or a subcutaneous port or any otherimplantable probe. Thus, the phrase “on-site parameters”, as usedherein, refers to physiological parameters which are obtainable byonline techniques.

Other that the trivial advantage of real-time on-site determination ofphysiological parameters, expressed mostly in the ability of apractitioner to respond immediately and manually to any critical changethereof, the data resulting from real-time online determination ofphysiological parameters can be fed into the machinery and be used forreal-time feedback controlling of the machinery. In the context ofembodiments of the present invention, the term “real-time” also relatesto systems that update information and respond thereto substantially atthe same rate they receive the information. Such real-time feedback canbe used to adhere to the treatment regimen and/or act immediately andautomatically in response to any critical deviations from acceptableparameters as a safety measure.

Hence, according to embodiments of the present invention, the term“on-site parameter” refers to physiological and/or mechanical and/orchemical datum which is obtainable and can be put to use orconsideration at or near the subject's site (e.g., bed-side) in arelatively short period of time, namely that the time period spanningthe steps of sampling, testing, processing and displaying/using thedatum is relatively short. An “on-site parameter” can be obtainable, forexample, in less than 30 minutes, less than 10 minutes, less than 5minutes, less than 1 minute, less than 0.5 minutes, less than 20seconds, less than 10 seconds, less than 5 seconds, or less than 1second from sampling to use. For example, the time period required toobtain on-site parameters by a technique known as pulse oximetry isalmost instantaneous; once the device is in place and set up, dataconcerning, e.g., oxygen saturation in the periphery of a subject, areavailable in less than 1 second from sampling to use.

In the context of some embodiments of the present invention, the phrase“off-site measurement and analysis techniques” or “off-site techniques”,refers to techniques that provide information regarding a givenphysiological parameter of the subject after sending a sample or rawdata to an offline, and typically off-site facility, and receiving theanalysis offline, sometimes hours or days after the sample had beenobtained. Off-site techniques are oftentimes based on samples collectedby mild invasive techniques, such as blood extraction for monitoringinflammatory cytokine plasma level, and invasive techniques, such asbiopsy, catheters or drainer tubus, however, some off-site techniquesrely on noninvasive sampling such as urine and stool chemistry offlineand off-site analyses. The phrase “off-site parameters”, as used herein,refers to physiological parameters which are obtainable by off-sitelaboratory techniques.

Hence, according to embodiments of the present invention, the term“off-site parameter” refers to physiological and/or mechanical and/orchemical datum which is obtain and can be put to use or consideration ina relatively long period of time, namely that the time period spanningthe steps of sampling, testing, processing and displaying/using thedatum is long compared to on-site parameters. Thus, an “off-siteparameter” is obtainable in more than 1 day, more than 12 hours, morethan 1 hour, more than 30 minutes, more than 10 minutes, or more than 5minutes from sampling to use.

An “off-site parameter” is typically obtainable upon subjecting a sampleto chemical, biological, mechanical or other procedures, which aretypically performed in a laboratory and hence are not performed“on-site”, namely by or near the subject's site.

Noninvasive measures for monitoring various physiological parametersinclude, without limitation, pulse oximetry, nonintubated respiratoryanalysis and/or capnometry. Mild invasive measures for monitoringvarious physiological parameters include, without limitation, bloodextraction, continuous blood gas and metabolite analysis, and in someembodiments intubated respiratory analysis and transcutaneous monitoringmeasures.

The term “pulse oximetry” refers to a noninvasive and on-site technologythat measures respiration-related physiological parameters by followinglight absorption characteristics of hemoglobin through the skin (finger,ear lobe etc.), and on the spectroscopic differences observed inoxygenated and deoxygenated species of hemoglobin, as well as hemoglobinspecies bound to other molecules, such as carbon monoxide (CO), andmethemoglobin wherein the iron in the heme group is in the Fe³⁺ (ferric)state. Physiological parameters that can be determined by pulse oximetryinclude SpO₂, SpMet and SpCO.

The phrase “nonintubated respiratory analysis”, as used herein, refersto a group of noninvasive and on-site technologies, such as spirometryand capnography, which provide measurements of the physiologicalpulmonary mechanics and respiratory gaseous chemistry by sampling theinhaled/exhaled airflow or by directing subject's breath to a detector,all without entering the subject's respiratory tract or other orificesnor penetrating the skin at any stage.

The term “spirometry” as used herein, refers to the battery ofmeasurements of respiration-related parameters and pulmonary functionsby means of a noninvasive and on-site spirometer. Following areexemplary spirometry parameters which may be used in the context of someembodiments of the present invention:

The spirometric parameter Tidal volume (TV) is the amount of air inhaledand exhaled normally at rest, wherein normal values are based onperson's ideal body weight.

The spirometric parameter Total Lung Capacity (TLC) is the maximumvolume of air present in the lungs.

The spirometric parameter Vital Capacity (VC) is the maximum amount ofair that can expel from the lungs after maximal inhalation, and is equalto the sum of inspiratory reserve volume, tidal volume, and expiratoryreserve volume.

The spirometric parameter Slow Vital Capacity (SVC) is the amount of airthat is inhaled as deeply as possible and then exhaled completely, whichmeasures how deeply a person can breathe.

The spirometric parameter Forced Vital Capacity (FVC) is the volume ofair measured in liters, which can forcibly be blown out after fullinspiration, and constitutes the most basic maneuver in spirometrytests.

The spirometric parameter Forced Expiratory Volume in the 1st second(FEV1) is the volume of air that can forcibly be blown out in onesecond, after full inspiration. Average values for FEV1 in healthypeople depend mainly on sex and age, whereas values falling between 80%and 120% of the average value are considered normal. Predicted normalvalues for FEV1 can be calculated on-site and depend on age, sex,height, weight and ethnicity as well as the research study that they arebased on.

The spirometric parameter FEV1/FVC ratio (FEV1%) is the ratio of FEV1 toFVC, which in healthy adults should be approximately 75-80%. Thepredicted FEV1% is defined as FEV1% of the patient divided by theaverage FEV1% in the appropriate population for that person.

The spirometric parameter Forced Expiratory Flow (FEF) is the flow (orspeed) of air coming out of the lung during the middle portion of aforced expiration. It can be given at discrete times, generally definedby what fraction remains of the forced vital capacity (FVC), namely 25%of FVC (FEF25), 50% of FVC (FEF50) or 75% of FVC (FEF75). It can also begiven as a mean of the flow during an interval, also generally delimitedby when specific fractions remain of FVC, usually 25-75% (FEF25-75%).Measured values ranging from 50-60% up to 130% of the average areconsidered normal, while predicted normal values for FEF can becalculated on-site and depend on age, sex, height, weight and ethnicityas well as the research study that they are based on. Recent researchsuggests that FEF25-75% or FEF25-50% may be a more sensitive parameterthan FEV1 in the detection of obstructive small airway disease. However,in the absence of concomitant changes in the standard markers,discrepancies in mid-range expiratory flow may not be specific enough tobe useful, and current practice guidelines recommend continuing to useFEV1, VC, and FEV1/VC as indicators of obstructive disease.

The spirometric parameter Negative Inspiratory Force (NIF) is thegreatest force that the chest muscles can exert to take in a breath,wherein values indicate the state of the breathing muscles.

The spirometric parameter MMEF or MEF refers to maximal (mid-)expiratoryflow and is the peak of expiratory flow as taken from the flow-volumecurve and measured in liters per second. MMEF is related to peakexpiratory flow (PEF), which is generally measured by a peak flow meterand given in liters per minute.

The spirometric parameter Peak Expiratory Flow (PEF) refers to themaximal flow (or speed) achieved during the maximally forced expirationinitiated at full inspiration, measured in liters per minute.

The spirometric parameter diffusing capacity of carbon monoxide(D_(L)CO) refers to the carbon monoxide uptake from a single inspirationin a standard time (usually 10 sec). On-site calculators are availableto correct D_(L)CO for hemoglobin levels, anemia, pulmonary hemorrhageand altitude and/or atmospheric pressure where the measurement wastaken.

The spirometric parameter Maximum Voluntary Ventilation (MVV) is ameasure of the maximum amount of air that can be inhaled and exhaledwithin one minute. Typically this parameter is determined over a 15second time period before being extrapolated to a value for one minuteexpressed as liters/minute. Average values for males and females are140-180 and 80-120 liters per minute respectively.

The spirometric parameter static lung compliance (Cst) refers to thechange in lung volume for any given applied pressure. Static lungcompliance is perhaps the most sensitive parameter for the detection ofabnormal pulmonary mechanics. Cst is considered normal if it is 60% to140% of the average value of a commensurable population.

The spirometric parameter Forced Expiratory Time (FET) measures thelength of the expiration in seconds.

The spirometric parameter Slow Vital Capacity (SVC) is the maximumvolume of air that can be exhaled slowly after slow maximum inhalation.

Static intrinsic positive end-expiratory pressure (static PEEPi) ismeasured as a plateau airway opening pressure during airway occlusion.

The spirometric parameter Maximum Inspiratory Pressure (MIP) is thevalue representing the highest level of negative pressure a person cangenerate on their own during an inhalation, which is expresented bycentimeters of water pressure (cmH₂O) and measured with a manometer andserves as n indicator of diaphragm strength and an independentdiagnostic parameter.

The term “capnography” refers to a technology for monitoring theconcentration or partial pressure of carbon dioxide (CO₂) in therespiratory gases. End-tidal CO₂, or ETCO₂, is the parameter that can bedetermined by capnography.

Gas detection technology is integrated into many medical and otherindustrial devices and allows the quantitative determination of thechemical composition of a gaseous sample which flows or otherwisecaptured therein. In the context of embodiments of the presentinvention, such chemical determination of gases is part of the on-site,noninvasive battery of tests, controlled and monitored activity of themethods presented herein. Gas detectors, as well as gas mixers andregulators, are used to determine and control parameters such asfraction of inspired oxygen level (FiO₂) and the concentration of nitricoxide in the inhaled gas mixture.

According to some embodiments of the present invention, the measurementof vital signs, such as heart rate, blood pressure, respiratory rate anda body temperature, is regarded as part of a battery of on-site andnoninvasive measurements.

The phrase “integrated pulmonary index”, or IPI, refers to a patient'spulmonary index which uses information on inhaled/exhaled gases fromcapnography and on gases dissolved in the blood from pulse oximetry toprovide a single value that describes the patient's respiratory status.IPI, which is obtained by on-site and noninvasive techniques, integratesfour major physiological parameters provided by a patient monitor(end-tidal CO₂ and respiratory rate as measured by capnography, andpulse rate and blood oxygenation SpO₂ as measured by pulse oximetry),using this information along with an algorithm to produce the IPI score.IPI provides a simple indication in real time (on-site) of the patient'soverall ventilatory status as an integer (score) ranging from 1 to 10.IP score does not replace current patient respiratory parameters, butused to assess the patient's respiratory status quickly so as todetermine the need for additional clinical assessment or intervention.

According to some of any of the embodiments described herein, themonitored physiological or chemical parameters include one or more ofthe following parameters:

a methemoglobin level (SpMet) (an on-line parameter);

an end-tidal CO₂ level (ETCO₂) (an on-line parameter);

an oxygenation level/FIO2 or oxygen saturation level (SpO₂) (an on-lineparameter);

an inflammatory cytokine plasma level (an off-line parameter); and

a serum nitrite/nitrate level (NO₂ ⁻/NO₃ ⁻) (an off-line parameter).

According to some of any of the embodiments described herein, themonitored physiological or chemical parameters further include one ormore of the following parameters:

a urine level of nitrogen dioxide (urine nitrite level) (an off-lineparameter);

a vital sign selected from the group consisting of a heart rate, a bloodpressure, a respiratory rate and a body temperature (an on-lineparameter);

a pulmonary function (spirometric parameter) (an on-line parameter) suchas, but not limited to, forced expiratory volume (FEV1), maximummid-expiratory flow

(MMEF), diffusing capacity of the lung for carbon monoxide (D_(L)CO),forced vital capacity (FVC), total lung capacity (TLC) and residualvolume (RV);

a hematological marker (an off-line parameter), such as, but not limitedto, a hemoglobin level, a hematocrit ratio, a red blood cell count, awhite blood cell count, a white blood cell differential and a plateletcount;

a coagulation parameter (an off-line parameter) such as, but not limitedto, a prothrombin time (PT), a prothrombin ratio (PR) and aninternational normalized ratio (INR);

a serum creatinine level (an off-line parameter);

a liver function marker (an off-line parameter) selected from the groupconsisting of a aspartate aminotransferase (AST) level, a serum glutamicoxaloacetic transaminase (SGOT) level, an alkaline phosphatase level,and a gamma-glutamyl transferase (GGT) level;

a vascular endothelial activation factor (an off-line parameter)selected from the group consisting of Ang-1, Ang-2 and Ang-2/Ang-1ratio.

Non-limiting examples of inflammatory cytokines include (TNF)α, (IL)-1ß,IL-6, IL-8, IL-10 and IL-12p70.

According to some embodiments of the present invention, the method asdisclosed herein is such that no substantial change in at least one ofthe monitored parameters is observed.

In the context of the present embodiments, a change in a parameter isconsidered substantial when a value of an observation (measurement, testresult, reading, calculated result and the likes) or a group ofobservations falls notably away from a normal level, for example fallsabout twice the upper limit of a normal level.

A “normal” level of a parameter is referred to herein as baseline valuesor simply “baseline”. In the context of the present embodiments, theterm “baseline” is defined as a range of values which have beendetermined statistically from a large number of observations and/ormeasurements which have been collected over years of medical practicewith respect to the general human population, a specific sub-set thereof(cohort) or in some cases with respect to a specific person. A baselineis a parameter-specific value which is generally and medically acceptedin the art as normal for a subject under certain physical conditions.These baseline or “normal” values, and means of determining these normalvalues, are known in the art. Alternatively, a baseline value may bedetermined from or in a specific subject before effecting the methoddescribed herein using well known and accepted methods, procedures andtechnical means. A baseline is therefore associated with a range oftolerated values, or tolerance, which have been determined inconjunction with the measurement of a parameter. In other words, abaseline is a range of acceptable values which limit the range ofobservations which are considered as “normal”. The width of thebaseline, or the difference between the upper and lower limits thereofare referred to as the “baseline range”, the difference from the centerof the range is referred to herein as the “acceptable deviation unit” orADU. For example, a baseline of 4-to-8 has a baseline range of 4 and anacceptable deviation unit of 2.

In the context of the present embodiments, a significant change in anobservation pertaining to a given parameter is one that falls more than2 acceptable deviation unit (2 ADU) from a predetermined acceptablebaseline. For example, an observation of 10, pertaining to a baseline of4-to-8 (characterized by a baseline range of 4, and an acceptabledeviation unit of 2), falls one acceptable deviation unit, or 1 AUD frombaseline. Alternatively, a change is regarded substantial when it ismore than 1.5 ADU, more than 1 ADU or more than 0.5 ADU.

In the context of the present embodiments, a “statistically significantobservation” or a “statistically significant deviation from a baseline”is such that it is unlikely to have occurred as a result of a randomfactor, error or chance.

It is noted that in some parameters or groups of parameters, thesignificance of a change thereof may be context-dependent, biologicalsystem-dependent, medical case-dependent, human subject-dependent, andeven measuring machinery-dependent, namely a particular parameter mayrequire or dictate stricter or looser criteria to determine if a readingthereof should be regarded as significant. It is noted herein that inspecific cases some parameters may not be measurable due to patientcondition, age or other reasons. In such cases the method is effectedwhile monitoring the other parameters.

A deviation from a baseline is therefore defined as a statisticallysignificant change in the value of the parameter as measured duringand/or following a full term or a part term of administration theregimen described herein, compared to the corresponding baseline of theparameter. It is noted herein that observations of some parameters mayfluctuate for several reasons, and a determination of a significantchange therein should take such events into consideration and correctthe appropriate baseline accordingly.

Monitoring methemoglobin and serum nitrite levels has been accepted inthe art as a required for monitoring the safety of gNO inhalation in asubject. Yet, to date, no clear indication that methemoglobin and serumnitrite levels remain substantially unchanged upon gNO inhalation by ahuman subject.

According to some embodiments of the present invention, the methodcomprises monitoring at least one of the parameters describedhereinabove.

According to some embodiments, the monitored parameter is methemoglobinlevel.

As methemoglobin levels can be measured using noninvasive measures, theparameter of percent saturation at the periphery of methemoglobin(SpMet) is used to monitor the stability, safety and effectiveness ofthe method presented herein. Hence, according to some embodiments of thepresent invention, the followed parameter is SpMet and during andfollowing the administration, the SpMet level does not exceed 5%, andpreferably does not exceed 1%. As demonstrated in the Examples sectionthat follows, a SpMet level of subjects undergoing the method describedherein does not exceed 1%.

According to some embodiments, the monitored parameter is serumnitrate/nitrite level.

High nitrite and nitrate levels in a subject's serum are associated withNO toxicity and therefore serum nitrite/nitrate levels are used todetect adverse effects of the method presented herein. According to someembodiments of the present invention, the tested parameter is serumnitrite/nitrate, which is monitored during and following the treatmentand the acceptable level of serum nitrite is less than 2.5micromole/liter and serum nitrate is less than 25 micromole/liter.

According to some embodiments, the monitored parameter is level ofinflammatory markers.

An elevation of inflammatory markers is associated with a phenomenoncalled “cytokine storm”, which has been observed in subjects undergoinggNO inhalation treatment.

Monitoring inflammatory markers while performing the method as describedherein has never been taught heretofore. Moreover, methods involving gNOinhalation at a regimen in which no significant change in inflammatorymarkers is observed have never been taught heretofore.

According to some embodiments, the method comprises monitoring at leasttwo of the above-mentions parameters.

In some of these embodiments, the monitored parameters are two or all ofmethemoglobin level, serum nitrite level and inflammatory markers.

While changes in methemoglobin level, serum nitrite level andinflammatory markers are typically observed in subjects subjected to gNOinhalation, the findings that no substantial change in these parametershas been observed in human subjects undergoing the disclosed regimen aresurprising.

Hence, according to some embodiments of the present invention, themethod as disclosed herein is carried out while monitoring themethemoglobin level (SpMet), the serum nitrite level (NO₂ ⁻) and a groupof inflammatory cytokine plasma level, such as, but not limited to,(TNF)α, (IL)-1ß, IL-6, IL-8, IL-10 and IL-12p70 serum levels in thesubject, wherein a change in at least one of these parameters is lessthan 2 acceptable deviation units from a baseline.

According to some of any of the embodiments described herein, the methodis effected while monitoring at least one, at least two, or all on-siteparameters which include SpMet, SpO₂ and ETCO₂, and/or monitoring atleast one or all off-site parameters which include serum nitrite/nitratelevel and inflammatory cytokines in the plasma.

For example, the method is effected while monitoring SpMet as an on-siteparameter. Alternatively, the method is effected while monitoring SpMetand ETCO₂ as on-site parameters. Alternatively, the method is effectedwhile monitoring SpMet, ETCO₂ and SpO₂ as on-site parameters.

Further alternatively, the method is effected while monitoring SpMet asone on-site parameter, and inflammatory cytokines in the plasma as oneoff-site parameter. Alternatively, the method is effected whilemonitoring SpMet and ETCO₂ as on-site parameters, and serumnitrite/nitrate level as one off-site parameter. Alternatively, themethod is effected while monitoring SpMet as one on-site parameter, andinflammatory cytokines in the plasma and serum nitrite/nitrate level asoff-site parameters. Alternatively, the method is effected whilemonitoring ETCO₂ as one on-site parameter, and inflammatory cytokines inthe plasma and serum nitrite/nitrate level as off-site parameters.Alternatively, the method is effected while monitoring SpO₂ as oneon-site parameter, and inflammatory cytokines in the plasma and serumnitrite/nitrate level as off-site parameters.

Further alternatively, the method is effected while monitoring SpMet,ETCO₂ and SpO₂ as on-site parameters, and inflammatory cytokines in theplasma and serum nitrite/nitrate level as off-site parameters.

According to some of any of the embodiments described herein, the methodis effected while monitoring at least one, at least two, or all on-siteparameters which include SpMet, SpO₂ and ETCO₂, and/or monitoring atleast one or all off-site parameters which include serum nitrite/nitratelevel and inflammatory cytokines in the plasma, and further monitoringone or more and in any combination of:

a urine NO₂ level (an off-line parameter);

a vital sign (an on-line parameter);

a pulmonary function (an on-line parameter);

a hematological marker (an off-line parameter);

a coagulation parameter (an off-line parameter);

a serum creatinine level (an off-line parameter);

a liver function marker (an off-line parameter);

a vascular endothelial activation factor (an off-line parameter).

According to some of any of the embodiments described herein, the methodis effected while monitoring at least one, at least two, or all on-sitechemical parameters in the inhaled gas mixture, such as FiO₂ and NO₂.

It is noted herein that for any of the abovementioned embodiments, thatthe method is effected while no substantial change is observed in anyone or more than one or all of the monitored parameters describedherein.

According to some embodiments of the present invention, the method iseffected while monitoring urine nitrite levels, such that the urinenitrite level is substantially unchanged during and subsequent tocarrying out the method as presented herein. It is noted herein thaturine nitrite levels may fluctuate for several known reasons, and adetermination of a significant change therein should take such eventsinto consideration and correct the appropriate baseline accordingly.

It is noted that urine nitrite level is indicative for the safety of gNOinhalation, yet, has never been monitored heretofore in the context ofgNO inhalation in general and in the context of intermittent gNOinhalation as disclosed herein.

According to some embodiments of the present invention, hematologicalmarkers, such as the hemoglobin level, the hematocrit ratio, the redblood cell count, the white blood cell count, the white blood celldifferential and the platelet count, are substantially unchanged duringand subsequent to carrying out the method as presented herein.

According to some embodiments of the present invention, vascularendothelial activation factors, such as Ang-1, Ang-2 and Ang-2/Ang-1ratio, as well as the serum creatinine level and various liver functionmarkers, such as the aspartate aminotransferase (AST) level, the serumglutamic oxaloacetic transaminase (SGOT) level, the alkaline phosphataselevel, and the gamma-glutamyl transferase (GGT) level, are substantiallyunchanged during and subsequent to carrying out the method as presentedherein.

Oxygenation of the subject can be assessed by measuring the subject'ssaturation of peripheral oxygen (SpO₂). This parameter is an estimationof the oxygen saturation level, and it is typically measured usingnoninvasive measures, such as a pulse oximeter device. Hence, accordingto some embodiments of the present invention, the followed parameterduring and following the administration is SpO₂, and the level of SpO₂is higher than about 89%.

According to some embodiments of the present invention, various vitalsigns, such as the heart rate, the blood pressure, the respiratory rateand the body temperature; and/or various pulmonary functions(spirometric parameter), such as forced expiratory volume (FEV₁),maximum mid-expiratory flow (MMEF), diffusing capacity of the lung forcarbon monoxide (D_(L)CO), forced vital capacity (FVC), total lungcapacity (TLC) and residual volume (RV); and various coagulationparameters, such as the prothrombin time (PT), the prothrombin ratio(PR) and the international normalized ratio (INR), are substantiallyunchanged during and subsequent to carrying out the method as presentedherein. It is noted that these parameters are regarded as an indicationthat the general health of the subject is not deteriorating as a resultof the medical condition and/or the treatment.

According to some embodiments, the aforementioned general healthindicators show an improvement during and subsequent to carrying out themethod as presented herein, indicating that the treatment is beneficialto the subject.

Thus, according to some embodiments of the present invention, the methodas disclosed herein is effected such that general health indicators asdescribed herein are at least remained unchanged or are improved.

According to some embodiments of the present invention, a human subjectin need of gNO inhalation treatment is a human that suffers from adisease or disorder of the respiratory tract.

As used herein, the phrase “respiratory tract” encompasses all organsand tissues that are involved in the process of respiration in a humansubject or other mammal subject, including cavities connected to therespiratory tract such as ears and eyes.

A respiratory tract, as used herein, encompasses the upper respiratorytract, including the nose and nasal passages, prenasal sinuses, pharynx,larynx, trachea, bronchi, and nonalveolar bronchioles; and the lowerrespiratory tract, including the lungs and the respiratory bronchioles,alveolar ducts, alveolar sacs, and alveoli therein.

Respiratory diseases and disorders which are treatable by any of themethods presented herein, can be classified as: Inflammatory lungdisease; Obstructive lung diseases such as COPD; Restrictive lungdiseases; Respiratory tract infections, such as upper/lower respiratorytract infections, and malignant/benign tumors; Pleural cavity diseases;pulmonary vascular diseases; and Neonatal diseases.

According to embodiments of the present invention, restrictive diseasesinclude intrinsic restrictive diseases, such as asbestosis caused bylong-term exposure to asbestos dust; radiation fibrosis, usually fromthe radiation given for cancer treatment; certain drugs such asamiodarone, bleomycin and methotrexate; as a consequence of anotherdisease such as rheumatoid arthritis; hypersensitivity pneumonitis dueto an allergic reaction to inhaled particles; acute respiratory distresssyndrome (ARDS), a severe lung condition occurring in response to acritical illness or injury; infant respiratory distress syndrome due toa deficiency of surfactant in the lungs of a baby born prematurely;idiopathic pulmonary fibrosis; idiopathic interstitial pneumonia, ofwhich there are several types; sarcoidosis; eosinophilic pneumonia;lymphangioleiomyomatosis; pulmonary Langerhans' cell histiocytosis;pulmonary alveolar proteinosis; interstitial lung diseases (ILD) such asinhaled inorganic substances: silicosis, asbestosis, berylliosis,inhaled organic substances: hypersensitivity pneumonitis, drug induced:antibiotics, chemotherapeutic drugs, antiarrhythmic agents, statins,connective tissue disease: Systemic sclerosis, polymyositis,dermatomyositis, systemic lupus erythematosus, rheumatoid arthritis,infection, atypical pneumonia, Pneumocystis pneumonia (PCP),tuberculosis, Chlamydia trachomatis, RSV, idiopathic sarcoidosis,idiopathic pulmonary fibrosis, Hamman-Rich syndrome, antisynthetasesyndrome, and malignant lymphangitic carcinomatosis; and extrinsicrestrictive diseases, such as neuromuscular diseases, includingMyasthenia gravis and Guillain barre; nonmuscular diseases of the upperthorax such as kyphosis and chest wall deformities; diseases restrictinglower thoracic/abdominal volume due to obesity, diaphragmatic hernia, orthe presence of ascites; and pleural thickening.

According to embodiments of the present invention, obstructive diseasesinclude asthma, COPD, chronic bronchitis, emphysema, bronchiectasis, CF,and bronchiolitis.

Respiratory diseases and disorders which are treatable by any of themethods presented herein, can also be classified as acute or chronic;caused by an external factor or an endogenous factor; or as infectiousor noninfectious respiratory diseases and disorders.

Diseases and disorders of the respiratory tract includeotolaryngological and/or an upper respiratory tract and/or a lowerrespiratory system diseases and disorders, and are also referred toherein as “respiratory diseases” or “respiratory diseases anddisorders”.

Exemplary, and most common, diseases and disorders of the respiratorytract include acute infections, such as, for example, sinusitis,bronchiolitis, tuberculosis, pneumonia, bronchitis, and influenza, andchronic conditions such as asthma, CF and chronic obstructive pulmonarydisease.

According to some embodiments of the present invention, subject in needof gNO inhalation treatment is a human subject that suffers from adisease or disorder that is manifested in the respiratory tract, asdefined herein.

In any of the embodiments described herein a human subject includes anyliving human at any age, from neonatals and newborns, to adults andelderly people, at any weight, height, and any other physical state.

A disease or disorder that is manifested in the respiratory tractencompasses also any disease or disorder that is not caused by aninfection or airway obstruction in the respiratory tract, rather, iscaused by another factor yet can be manifested by an infection or airwayobstruction in the respiratory tract.

An exemplary such condition is cystic fibrosis (CF). CF is a geneticdisorder in which mutations in the epithelial chloride channel, CFtransmembrane conductance regulator (CFTR), impairs various mechanism ofinnate immunity. Chronic microbial lung infections are the leading causeof morbidity and mortality in CF patients. Early antibiotic eradicationtreatment of CF patients for the most prevalent bacterial pathogen,Pseudomonas aeruginosa, has considerably increased the life expectancyin CF, however still the vast majority of adult CF patients suffer fromchronic P. aeruginosa lung infections which are difficult to treat dueto biofilm formation and the development of antibiotic resistant strainsof the virulent. Other species found in CF airways include antibioticresistant strains such as methicillin-resistant S. aureus (MRSA),members of the Burkholderia cepacia complex, Haemophilus influenzae,Stenotrophomonas maltophilia, Achromobacter xylosoxidans,non-tuberculous Mycobacteria (NTM) species and various strict anaerobicbacteria.

According to some embodiments of the present invention, a human subjectin need of gNO inhalation treatment is a human subject that is prone tosuffer from a respiratory tract disease or disorder. By “prone tosuffer” it is meant that the human subject is at a higher risk ofsuffering from the disease or disorder compared to a normal subject.

Such human subjects include, for example, immuno-compromised subjectssuch as subjects having HIV, cancer patients undergoing or whichunderwent chemotherapy, cancer and other patients undergoing or whichunderwent transplantation, including bone marrow transplantation andtransplantation of a solid organ, subjects with chronic asthma orsinusitis, and subjects which were in contact with subject(s) afflictedby an infectious respiratory tract disease or disorder, or which haveotherwise been exposed to a pathogen. It is noted herein that subjectinga human subject prone to suffer from a respiratory tract disease ordisorder to the gNO inhalation treatment presented herein, can beregarded as a preventative treatment, preventive care, or as aprophylactic medical treatment.

Alternatively, a human subject in need of gNO treatment is animmuno-compromised subject such as subjects having HIV, cancer patientsundergoing or which underwent chemotherapy, cancer and other patientsundergoing or which underwent transplantation, including bone marrowtransplantation and transplantation of a solid organ, which have beeninfected or otherwise suffer from a respiratory disease or disorder asdescribed herein.

Exemplary diseases or disorders of such immune-compromised subjects aredescribed in more detail hereinbelow.

According to some embodiments of the present invention, a human subjectin need of gNO inhalation treatment is a human subject that suffers froma disease or disorder that is treatable via the respiratory tract.

Since inhaled gNO is absorbed in the lungs, it contacts the blood systemand hence can reach other tissues and organs in the biological system.Thus, diseases and disorders that are not associated directly to therespiratory tract, yet can be treated by inhalation of agents that showtherapeutic effect on such diseases and disorders, can be treatedaccording to embodiments of the present invention. Exemplary suchdiseases and disorders include, but are not limited to, acidosis,sepsis, leishmaniasis, and various viral infections.

The parasite family, Leishmania, has been extensively studied in theliterature which shows that gNO kills the parasite directly. Leishmaniaparasites preferentially infect macrophages. Infection by Leishmaniacauses the macrophage to produce IFN-gamma which induces the productionof iNOS, an enzyme responsible for the production of nitric oxide.However, certain presentations of Leishmania cause the macrophage toalso produce IL-10 and TGF-Beta which both minimize the induction ofiNOS. The decrease in NO levels is a key factor allowing the infectionto continue. It would therefore be highly beneficial to determine iftreatment with gNO inhalation circumvents the defense system of theparasite. Nonetheless, gNO administered by inhalation at anyconcentration has not been demonstrated as safe or effective againstleishmaniasis hitherto.

Additional such diseases and disorders include viral infections. Viruseshave been and most likely will stay a challenging “moving target” formodern medicinal methodologies. Without cell walls and thiol baseddetoxification pathways, viruses may be inherently more susceptible tonitrosative stress. Several in-vitro studies, using NO donors, as opposeto gNO, have demonstrated that NO inhibits viral ribonucleotidereductase, a necessary constituent enzyme of viral DNA synthesis andtherefore inhibit viral replication. It has been demonstrated that NOinhibits the replication of viruses early during the replication cycle,involving the synthesis of vRNA and mRNA encoding viral proteins. Otherdirect mechanisms could also account for the viricidal effects throughviral DNA deamination. Nonetheless, gNO administered by inhalation hasnot been demonstrated as safe or effective against acute viralinfections or as a prophylactic viral treatment hitherto.

The present inventors have demonstrated that the use of supraphysiologicconcentrations of gNO administered by inhalation may provide a broadspectrum, non-specific antiviral activity to be used at various stagesof infection. The present inventors have tested two strains of humaninfluenza (influenza A/victoria H3N2) and one strain of highlypathogenic avian influenza (H7N2), as well as human respiratorysyncytial virus (rgRSV30), using the traditional plaque or fluorescenceassays, and demonstrated that treating RSV and influenza with 160 ppmexogenous gaseous NO reduced their infectivity.

According to some embodiments of the present invention, a human in needof gNO inhalation is a human afflicted by a disease or disorder that istreatable by gNO. The range of treatable diseases and disorders spansophthalmological, otolaryngological and/or an upper respiratory tractand/or a lower respiratory system diseases and disorders, as well assystemic medical conditions.

Exemplary diseases and disorders treatable by gNO include, withoutlimitation, a heparin-protamine reaction, a traumatic injury, atraumatic injury to the respiratory tract, acidosis or sepsis, acutemountain sickness, acute pulmonary edema, acute pulmonary hypertension,acute pulmonary thromboembolism, adult respiratory distress syndrome, anacute pulmonary vasoconstriction, aspiration or inhalation injury orpoisoning, asthma or status asthmaticus, bronchopulmonary dysplasia,hypoxia or chronic hypoxia, chronic pulmonary hypertension, chronicpulmonary thromboembolism, cystic fibrosis (CF), Aspergilosis,aspergilloma, Cryptococcosis, fat embolism of the lung, haline membranedisease, idiopathic or primary pulmonary hypertension, inflammation ofthe lung, perinatal aspiration syndrome, persistent pulmonaryhypertension of a newborn and post cardiac surgery.

According to some embodiments of the present invention, exemplarytreatable diseases or disorders include, without limitation, abacterial-, viral- and/or fungal bronchiolitis, a bacterial-, viral-and/or fungal pharyngitis and/or laryngotracheitis, a bacterial-, viral-and/or fungal pneumonia, a bacterial-, viral- and/or fungal pulmonaryinfection, a bacterial-, viral- and/or fungal sinusitis, a bacterial-,viral- and/or fungal upper and/or lower respiratory tract infection, abacterial-, viral- and/or fungal-exacerbated asthma, a respiratorysyncytial viral infection, bronchiectasis, bronchitis, chronicobstructive lung disease (COPD), cystic fibrosis (CF), Aspergilosis,aspergilloma, Cryptococcosis, emphysema, otitis, a bacterial-, viral-and/or fungal otitis externa, otitis media, conjunctivitis, uveitisprimary ciliary dyskinesia (PCD) and pulmonary aspergillosis (ABPA).

According to some embodiments of the present invention, the disease ordisorder treatable by gNO is associated with a pathogenic microorganism.The pathogenic microorganisms, according to some embodiments of thepresent invention, can be, for example, Gram-negative bacteria,Gram-positive bacteria, viruses and viable virions, fungi and parasites.

Exemplary pathogenic microorganisms include, but are not limited to,Acinetobacter baumarmii, Aspergillus niger, Bacteroides vulgatus,Burkoholderia cepacia, Candida albicans, Clostridium perfringens,Enteric Group 137, Enterococcus faecium, Enterobacter aerogenes,Escherichia cofi, Klebsiella pneumoniae, Mycobacteria tuberculosis,Pasteurella multocida, Propionibacterium acnes, Propionibacteriumgranulosum, Proteus mirabilis, Providencia rusfigianii, Pseudomonasaeruginosa, Pseudomonas sp., Serratia marcesecens, Staphylococcusaureus, Staphylococcus aureus (FVL positive), Staphylococcus aureus (VNLpositive), Staphylococcus aureus MRSA, Staphylococcus aureus MRSA,Staphylococcus aureus MRSA, Streptococci Group B, Streptococci Group D,Streptococci Group G, Streptococcipyrogenes rosenbach Group A,Streptococcus pneumoniae, Trichophyton meriagrophytes, Trichophytonrubrum, and Vibrio vuMucus.

Exemplary Gram-negative bacteria include, but are not limited to,Proteobacteria, Enterobacteriaceae, Acinetobacter baumannii,Bdellovibrio, Cyanobacteria, Enterobacter cloacae, Escherichia coli,Helicobacter, Helicobacter pylori, Hemophilus influenza, Klebsiellapneumonia, Legionella, Legionella pneumophila, Moraxella, Moraxellacatarrhalis, Neisseria gonorrhoeae, Neisseria meningitides, Proteusmirabilis, Pseudomonas, Pseudomonas aeruginosa, Salmonella, Salmonellaenteritidis, Salmonella typhi, Serratia marcescens, Shigella,Spirochaetes and Stenotrophomonas.

Exemplary Gram-positive bacteria include, but are not limited to,Bacillus species such as B. alcalophilus, B. alvei, B. aminovorans, B.amyloliquefaciens, B. aneurinolyticus, B. anthracis, B. aquaemaris, B.atrophaeus, B. boroniphilus, B. brevis, B. caldolyticus, B.centrosporus, B. cereus, B. circulans, B. coagulans, B. firmus, B.flavothermus, B. fusiformis, B. globigii, B. infernus, B. larvae, B.laterosporus, B. lentus, B. licheniformis, B. megaterium, B.mesentericus, B. mucilaginosus, B. mycoides, B. natto, B.pantothenticus, B. polymyxa, B. pseudoanthracis, B. pumilus, B.schlegelii, B. sphaericus, B. sporothermodurans, B. stearothermophilus,B. subtilis, B. thermoglucosidasius, B. thuringiensis, B. vulgatis andB. weihenstephanensis, Clostridium species such as C. acetobutylicum, C.aerotolerans, C. argentinense, C. baratii, C. beijerinckii, C.bifermentans, C. botulinum, C. butyricum, C. cadaveris, C.cellulolyticum, C. chauvoei, C. clostridioforme, C. colicanis, C.difficile, C. estertheticum, C. fallax, C. feseri, C. formicaceticum, C.histolyticum, C. innocuum, C. kluyveri, C. lavalense, C. ljungdahlii, C.novyi, C. oedematiens, C. paraputrificum, C. perfringens, C.phytofermentans, C. piliforme, C. ragsdalei, C. ramosum, C.scatologenes, C. septicum, C. sordellii, C. sporogenes, C. sticklandii,C. tertium, C. tetani, C. thermocellum, C. thermosaccharolyticum, C.tyrobutyricum, Corynebacterium species such as C. accolens, C.afermentans, C. amycolatum, C. aquaticum, C. argentoratense, C. auris,C. bovis, C. diphtheriae, C. equi, C. flavescens, C. glucuronolyticum,C. glutamicum, C. granulosum, C. haemolyticum, C. halofytica, C.jeikeium, C. macginleyi, C. matruchotii, C. minutissimum, C. parvum, C.propinquum, C. pseudodiphtheriticum, C. pseudotuberculosis, C. pyogenes,C. renale, C. spec, C. striatum, C. tenuis, C. ulcerans, C. urealyticum,C. urealyticum and C. xerosis, Listeriai species such as L. grayi, L.innocua, L. ivanovii, L. monocytogenes, L. murrayi, L. seeligeri and L.welshimeri, Staphylococcus species such as S. arlettae, S. aureus, S.auricularis, S. capitis, S. caprae, S. carnosus, S. chromogenes, S.cohnii, S. condimenti, S. delphini, S. devriesei, S. epidermidis, S.equorum, S. felis, S. fleurettii, S. gallinarum, S. haemolyticus, S.hominis, S. hyicus, S. intermedius, S. kloosii, S. leei, S. lentus, S.lugdunensis, S. lutrae, S. massiliensis, S. microti, S. muscae, S.nepalensis, S. pasteuri, S. pettenkoferi, S. piscifermentans, S.pseudintermedius, S. pseudolugdunensis, S. pulvereri, S. rostri, S.saccharolyticus, S. saprophyticus, S. schleiferi, S. sciuri, S. simiae,S. simulans, S. stepanovicii, S. succinus, S. vitulinus, S. warneri andS. xylosus, and Streptococcus species such as S. agalactiae, S.anginosus, S. bovis, S. canis, S. constellatus, S. dysgalactiae, S.equinus, S. iniae, S. intermedius, S. mitis, S. mutans, S. oralis, S.parasanguinis, S. peroris, S. pneumoniae, S. pyogenes, S. ratti, S.salivarius, S. sanguinis, S. sobrinus, S. suis, S. thermophilus, S.uberis, S. vestibularis, S. viridians and S. zooepidemicus.

As discussed hereinabove, and demonstrated in the Examples section thatfollows below, the disease or disorder which can be treated by effectingthe method presented herein to a human subject, includes bacterial-,viral- and/or fungal bronchiolitis, bacterial-, viral- and/or fungalpharyngitis and/or laryngotracheitis, bacterial-, viral- and/or fungalsinusitis, bacterial-, viral- and/or fungal upper and/or lowerrespiratory tract infection, bacterial-, viral- and/orfungal-exacerbated asthma, bacterial-, viral-, fungal- and/or parasiticpneumonia, the common cold, cystic fibrosis related infections,aspergillosis, aspergilloma, respiratory syncytial viral infections,acidosis or sepsis, oral fugal infections, bronchitis, candidiasis ofthe oral cavity (thrush), canker sores, epiglottitis (supraglottitis),halitosis, herpes, laryngitis, laryngotracheitis, nasopharyngitis,otitis externa and otitis media, conjunctivitis, uveitis (and other eyeinfections) pharyngitis, pulmonary aspergillosis (ABPA), respiratorysyncytial virus infections, rhinitis, rhinopharyingitis, rhinosinusitis,stomatitis, tonsillitis, tracheitis, tuberculosis, cryptococcosis andtympanitis.

According to some embodiments of the present invention, a human subjectin need of gNO inhalation is a human subject in need of preemptive,preventative and prophylactic treatment of a disease or disorder asdescribed herein. Hence, a subject not suffering from any current ormanifested disease, and/or a subject that is suspected of being exposedto a pathogen, and/or a subject that suffers from one disease, istreated by the method(s) presented herein in order to prevent theoccurrence of another disease or disorder.

As presented in the Examples section that follows below, the presentinventors have contemplated treating bronchiolitis as this condition isdefined hereinbelow. Hence, according to an aspect of some embodimentsof the present invention, there is provided a method of treating a humansubject suffering from bronchiolitis, which is effected by subjectingthe subject to intermittent inhalation regimen, gNO at a concentrationof at least 160 ppm, thereby treating bronchiolitis.

It is noted herein that the treatable bronchiolitis, according to someembodiments of the present invention, can be associated with apathogenic microorganism or not associated therewith. It is thereforenoted that the method presented herein can be used to treat idiopathicbronchiolitis, bacterial- and/or viral-induced bronchiolitis and/orbronchiolitis that is associated with other medical conditions such as,but not limited to, immune deficiency.

In some embodiments, the bronchiolitis is a viral-induced bronchiolitis.Exemplary viral infections that are known to be manifested bybronchiolitis include, but not limited to, respiratory syncytial viruses(RSV), rhinoviruses, coronaviruses, enteroviruses, influenza A and/or Bviruses, parainfluenza 1, 2 and/or 3 viruses, bocaviruses, humanmetapneumoviruses, SARS and adenoviruses. However, infections caused byany other viruses are also contemplated.

The findings that high concentration of inhaled gNO, which was shown toexhibit a therapeutic effect against a variety of conditions associatedwith pathogenic microorganisms, can be safely used in human subjectsindicate that the disclosed intermittent inhalation of gNO can beefficiently utilized for treating such conditions, as well as any otherconditions that are treatable by gNO when contacting the respiratorytract.

Hence, according to an aspect of some embodiments of the presentinvention, there is provided a method of treating a human subjectsuffering from a disease or a disorder which is associated, directly orindirectly, with a pathogenic microorganism, as described herein. Themethod is effected by subjecting the subject to intermittent inhalationregimen of gNO at a concentration of at least 160 ppm, as described inany of the present embodiments.

According to another aspect of some embodiments of the presentinvention, there is provided a method of treating a human subjectsuffering from a disease or disorder that is manifested in therespiratory tract or a disease or disorder that can be treated via therespiratory tract, which is effected by subjecting the subject tointermittent inhalation regimen, gNO at a concentration of at least 160ppm, as described in any of the present embodiments.

According to another aspect of some embodiments of the presentinvention, there is provided a method of treating a human subject proneto suffer from a disease or disorder that is manifested in therespiratory tract or a disease or disorder that can be treated via therespiratory tract, as described herein, which is effected by subjectingthe subject to intermittent inhalation regimen, gNO at a concentrationof at least 160 ppm, as described in any of the present embodiments.Such a method can be regarded as a preventive or prophylaxis treatmentof the subject.

According to another aspect of some embodiments of the presentinvention, there is provided a method of treating a human subjectsuffering from an ophthalmological, otolaryngological and/or upperrespiratory tract disease or disorder, as described herein, which iseffected by subjecting the subject to intermittent inhalation regimen,gNO at a concentration of at least 160 ppm, as described in any of thepresent embodiments.

According to some embodiments of the present invention, theotolaryngological and/or upper respiratory tract disease and disorderinvolves an infection or an inflammation of a bodily site selected fromthe group consisting of an ear cavity, a nasal cavity, a sinus cavity,an oral cavity, a pharynx, a epiglottis, a vocal cord, a trachea, anapex and an upper esophagus.

According to some embodiments of the present invention, theophthalmological, otolaryngological and/or upper respiratory tractdiseases and disorders include, without limitation, the common cold, astomatognathic disease, amigdalitis, an oral fugal infection,bacterial-, viral- and/or fungal sinusitis, bronchitis, candidiasis ofthe oral cavity (thrush), canker sores, epiglottitis (supraglottitis),halitosis, herpes, laryngitis, laryngotracheitis, nasopharyngitis,otitis (externa and media), conjunctivitis, uveitis and other eyeinfections, pharyngitis, rhinitis, rhinopharyingitis, rhinosinusitis,stomatitis, tonsillitis, tracheitis, tracheitis and tympanitis.

According to another aspect of some embodiments of the presentinvention, there is provided a method of treating a human subjectsuffering from a disease or disorder of the lower respiratory system, asdescribed herein, by intermittent inhalation regimen, gNO at aconcentration of at least 160 ppm, as described in any of theembodiments herein.

According to some embodiments of the present invention, diseases anddisorders of the lower respiratory system include, without limitation,an obstructive condition, a restrictive condition, a vascular diseaseand an infection, an inflammation due to inhalation of foreign matterand an inhaled particle poisoning.

According to some embodiments of the present invention, the obstructivecondition includes, without limitation, a chronic obstructive lungdisease (COPD), emphysema, bronchiolitis, bronchitis, asthma and viral,bacterial and fungal exacerbated asthma; the restrictive conditionincludes, without limitation, fibrosis, cystic fibrosis, sarcoidosis,alveolar damage and pleural effusion; the vascular disease includes,without limitation, pulmonary edema, pulmonary embolism and pulmonaryhypertension; the infection includes, without limitation, respiratorysyncytial virus infection, tuberculosis, a viral-, bacterial-, fungal-,and/or parasitic pneumonia, idiopathic pneumonia; and the inflammationdue to inhalation of foreign matter and an inhaled particle poisoningincludes, without limitation, smoke inhalation, asbestosis and exposureto particulate pollutants and fumes.

According to some embodiments of the present invention, any of themethods of treating or preventing a subject as described hereinencompasses all of the conditions, disease and disorders describedhereinabove for subjects in need of gNO inhalation.

It is noted herein that any of the methods described herein can be usedbeneficially to treat bronchiolitis, which occurs in infants andchildren. Administration by inhalation is considered to be a preferredmethod of for young patients and more so when invasive techniques areavoided.

Influenza of all sorts and types is also treatable by the methodspresented herein, and where some embodiments being based on a relativelysimple and noninvasive technique, these methods are particularlypreferred in complicated and severe cases of influenza.

The methods presented herein are effective in treating asthma inchildren and adults, as well as treating COPD and CF.

The methods presented herein are fast and effective in treating a resentmedical condition, disease or disorder. Moreover, the methods presentedherein are effective in preventing the disease or disorder from takinghold in a subject which is prone to suffer from, contract or develop adisease or disorder which is associated with the respiratory tract.According to some embodiments, some methods of gNO inhalation areparticularly useful in preventing a disease or disorder, while othermethods are particularly effective in treating an existing disease ordisorder.

According to some embodiments of the present invention, any of themethods described herein can be used in the context of the followingconditions:

Any of the methods presented herein can be used effectively to treatrespiratory diseases or disorders that occur in humans which arediagnosed with medical conditions that adversely affect their innateimmune system. Humans which are diagnosed with such medical conditionsare said to be immuno-compromised or immuno-suppressed. It is notedherein that immuno-suppression may be a direct result of a pathogen,such as an HIV infection, or an indirect result such asimmuno-suppression that occurs in cancer patients being treated withchemotherapeutic agents. Hence, according to some embodiments of thepresent invention, the methods presented herein are used to treat apresent respiratory disease or disorder in immuno-compromised humansubject.

Immuno-compromised or immuno-suppressed human subjects are intrinsicallymore susceptible to opportunistic infections, rendering them prone tosuffer from respiratory diseases or disorders. Other incidents andconditions that render a human more susceptible to infections areassociated with location, occupation, age, living and environmentalconditions, close contact with large groups of people and livestock,close contact with sick people and the likes, all of which areencompassed in the context of the present invention as rendering a humansubject prone to suffer from a respiratory disease or disorder.

According to some embodiments of the present invention, any of themethods presented herein are used to treat opportunistic infections in ahuman subject.

Exemplary opportunistic infections, which occur in human suffering fromHIV, and can be treated or prevented by the methods presented hereininclude, without limitation Pneumocystis jiroveci infection,Pneumocystis carinii infection and Pneumocystis pneumonia (a form ofpneumonia caused by the yeast-like fungus).

Exemplary medical conditions which are associated with immunosuppressioninclude AIDS, cancer, primary ciliary dyskinesia (PCD, also known asimmotile ciliary syndrome or Kartagener Syndrome).

According to some embodiments of the present invention, any of themethods presented herein is used to treat a human subject suffering fromAIDS.

According to some embodiments of the present invention, any of themethods presented herein are used to treat a human subject sufferingfrom cancer.

According to some embodiments of the present invention, any of themethods presented herein can be used to treat or prevent an infectionassociated with immune deficiency. These include prevention/pre-emptivetreatment and treatment of infections in oncology patients.

According to some embodiments of the present invention, in any of themethods presented herein the human subject is at risk of suffering froma nosocomial infection.

Exemplary groups of human subject which are prone to suffer respiratorydisease or disorder due to general, environmental and occupationalconditions include, without limitation, elderly people, medical staffand personnel (doctors, nurses, caretakers and the likes) of medicalfacilities and other care-giving homes and long-term facilities,commercial airline crew and personnel (pilots, flight attendants and thelikes), livestock farmers and the likes.

According to some embodiments, the methods presented herein are used totreat or prevent nosocomial infections, such s infections stemming fromdirect-contact transmission, indirect-contact transmission, droplettransmission, airborne transmission, common vehicle transmission andvector borne transmission. Exemplary nosocomial infections are caused byantibiotic resistant bacteria such as carbapenem-resistant Klebsiella(KPC) or other Enterobacteriaceae, MRSA methicillin resistance Staph.aureus, Group A Streptococcus, Staphylococcus aureus (methicillinsensitive or resistance), Neisseria meningitides of any serotype and thelikes.

Hence, according to embodiments of the present invention, the methodspresented herein can be used to prevent carriage, transmission andinfection of pathogenic bacteria and antibiotic resistant pathogenicmicroorganisms.

According to some embodiments of the present invention, any of themethods of treatment presented herein further includes monitoring,during and following administration gNO, one or more of the parametersas described in any of the embodiments hereinabove.

In some embodiments, the methods are effected while monitoring one, two,etc., or all of:

a methemoglobin level (SpMet) (an on-line parameter);

an end-tidal CO₂ level (ETCO₂) (an on-line parameter);

an oxygenation level or oxygen saturation level (SpO₂) (an on-lineparameter);

an inflammatory cytokine plasma level (an off-line parameter); and

a serum nitrite/nitrate level (NO₂ ⁻/NO₃ ⁻) (an off-line parameter).

In some embodiments, no significant deviation from baseline, asdescribed herein, is shown in at least one, two, three, four or all ofthe above parameters, when monitored, as described herein.

Other parameters and markers may be monitored as well, as presentedhereinabove, while showing significant deviation from a baseline, andvarious general health indicators show no change to the worse, or animprovement, as presented hereinabove.

According to some embodiments of the present invention, in any of themethods of treatment presented herein, the gNO administration can beeffected by an inhalation device which includes, without limitation, astationary inhalation device, a portable inhaler, a metered-dose inhalerand an intubated inhaler.

An inhaler, according to some embodiments of the present invention, cangenerate spirometry data and adjust the treatment accordingly over timeas provided, for example, in U.S. Pat. No. 5,724,986 and WO 2005/046426.The inhaler can modulate the subject's inhalation waveform to targetspecific lung sites. According to some embodiments of the presentinvention, a portable inhaler can deliver both rescue and maintenancedoses of gNO at subject's selection or automatically according to aspecified regimen.

According to some embodiments of the present invention, an exemplaryinhalation device may include a delivery interface adaptable forinhalation by a human subject.

According to some embodiments of the present invention, the deliveryinterface includes a mask or a mouthpiece for delivery of the mixture ofgases containing gNO to a respiratory organ of the subject.

According to some embodiments of the present invention, the inhalationdevice further includes a gNO analyzer positioned in proximity to thedelivery interface for measuring the concentration of gNO, oxygen andnitrogen dioxide flowing to the delivery interface, wherein the analyzeris in communication with the controller.

According to some embodiments of the present invention, subjecting thesubject to the method described herein is carried out by use of aninhalation device which can be any device which can deliver the mixtureof gases containing gNO to a respiratory organ of the subject. Aninhalation device, according to some embodiments of the presentinvention, includes, without limitation, a stationary inhalation devicecomprising tanks, gauges, tubing, a mask, controllers, values and thelikes; a portable inhaler (inclusive of the aforementioned components),a metered-dose inhaler, a an atmospherically controlled enclosure, arespiration machine/system and an intubated inhalation/respirationmachine/system. An atmospherically controlled enclosure includes,without limitation, a head enclosure (bubble), a full body enclosure ora room, wherein the atmosphere filling the enclosure can be controlledby flow, by a continuous or intermittent content exchange or any otherform of controlling the gaseous mixture content thereof.

It is expected that during the life of a patent maturing from thisapplication many relevant medical procedures involving inhalation of gNOwill be developed and the scope of the term treatment by inhalation ofgNO is intended to include all such new technologies a priori.

As used herein the term “about” refers to ±10%.

The terms “comprises”, “comprising”, “includes”, “including”, “having”and their conjugates mean “including but not limited to”.

The term “consisting of” means “including and limited to”.

The term “consisting essentially of” means that the composition, methodor structure may include additional ingredients, steps and/or parts, butonly if the additional ingredients, steps and/or parts do not materiallyalter the basic and novel characteristics of the claimed composition,method or structure.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise. For example,the term “a compound” or “at least one compound” may include a pluralityof compounds, including mixtures thereof.

Throughout this application, various embodiments of this invention maybe presented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible subranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween.

As used herein the term “method” refers to manners, means, techniquesand procedures for accomplishing a given task including, but not limitedto, those manners, means, techniques and procedures either known to, orreadily developed from known manners, means, techniques and proceduresby practitioners of the chemical, pharmacological, biological,biochemical and medical arts.

As used herein, the term “treating” includes abrogating, substantiallyinhibiting, slowing or reversing the progression of a condition,substantially ameliorating clinical or aesthetical symptoms of acondition, and substantially preventing the appearance of clinical oraesthetical symptoms of a condition, namely preemptive, preventative andprophylactic treatment.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination or as suitable in any other describedembodiment of the invention. Certain features described in the contextof various embodiments are not to be considered essential features ofthose embodiments, unless the embodiment is inoperative without thoseelements.

Various embodiments and aspects of the present invention as delineatedhereinabove and as claimed in the claims section below find experimentalor calculated support in the following examples.

EXAMPLES

Reference is now made to the following examples, which together with theabove descriptions illustrate some embodiments of the invention in a nonlimiting fashion.

Example 1 (Background Art) Determination of Effective AntimicrobialLevel of gNO

The direct effect of gNO on bacteria was studied by determining theconcentration of gNO which is lethal for microbes. Once an optimal dosewas estimated, timing study was conducted to optimize the duration ofexposure of the microbes to gNO.

For these initial studies, highly dense inoculums of P. aeruginosa andS. aureus suspensions (10⁸ chum) were plated onto agar plates. Theseplates were then exposed to various concentrations of gNO in an exposuredevice in order to evaluate the effect on colony growth.

FIGS. 1A-B present bar-plot showing the gNO dosage curve on as measuredfor S. aureus (FIG. 1A) and P. aeruginosa (FIG. 1B) grown on solidmedia, wherein relative percentage of growth of colony forming units(CFU) at 50, 80, 120 and 160 parts per million (ppm) of gaseous nitricoxide (gNO) compared with growth of CFU in medical air (100%).

As can be seen in FIGS. 1A-B, the results confirmed that gNO has aninhibitory effect on P. aeruginosa and S. aureus growth. The dataprovided preliminary evidence that there was a time and doserelationship trend, with the amount of bactericidal (antibiotic)activity increasing with increased time of exposure and concentration ofgNO. As the concentration of gNO increased, the number of coloniesgrowing on the plates decreased. Although there was a downwardbactericidal trend towards 5-10% survival, none of the data showed a100% bactericidal effect. Some bacteria may have survived because thematerials and chemicals in the agar may have reacted with the gNO andbuffered the effect.

It is noted that bacterial colonies remained the same in size and numberafter being transferred to a conventional incubator for 24 hours,whereas controls increased in number and size to the degree that theycould not be counted. This observation suggested that gNO exposureprevented the growth of the bacteria, and may have killed the bacteriaat some point during the gNO exposure.

These results demonstrated that gNO had a bacteriostatic effect on bothbacterial strains, and as a result, subsequent studies were designed tofurther study the bactericidal effects of gNO. The studies demonstratedthat levels of gNO greater than 120 ppm reduced the colony formation bygreater than 90%. Studies then followed indicating that the timerequired to achieve this effect occurred between 8-12 hours.

A similar procedure was used to determine the time required to induce aneffective bactericidal effect with 200 parts per million gNO, aconcentration just above the dose used in the dose-ranging studypresented hereinabove, on a representative collection of drug resistantgram-positive and gram-negative strains of bacteria associated withclinical infection.

A successful bactericidal effect was defined as a decrease in bacteriagreater than 3 log₁₀ CFU/mL. Further, C. albicans, Methicillin ResistantS. aureus (MRSA), a particularly resistant strain of P. aeruginosa froma cystic fibrosis patient, Group B Streptococcus, and M. smegmatis werealso included to evaluate if yeasts, a multi-drug resistant strain ofbacteria and actinomycetes have a similar response. These bacteriarepresent a comprehensive variety of drug resistant bacterial pathogensthat contribute to both respiratory and wound infections. The resultsfrom these studies laid the foundation for use of gNO at a concentrationhigher than 160 ppm as an antibacterial agent, specifically for useagainst bacteria associated with clinical infections.

For this study, saline was selected as a suspension media because itwould not mask the direct effect of gNO as a bactericidal, whereas fullysupplemented growth medium might introduce external variables (e.g.,buffer or react with gNO). Other media might also provide metabolitesand replenish nutrients that produce enzymes that protect bacteria fromoxidative and nitrosative damage, thereby masking the effect of gNO.Furthermore, it has been suggested that a saline environment betterrepresents the hostile host environment that bacteria typically areexposed to in vivo. In saline, the colonies were static but remainedviable. These conditions are similar to the approach previously used inanimal models.

Table 1 present the results of this study of the effect of 200 ppm gNOon a variety of microbes.

TABLE 1 Latent Gram Period −2.5 Log₁₀ LD₁₀₀ Bacteria Staining (hours)(hours) (hours) S. aureus (ATCC) Positive 3 3.3 4 P. aeruginosa (ATCC)Negative 1 2.1 3 MRSA Positive 3 4.2 5 Serracia sp. Negative 4 4.9 6 S.aureus (Clinical) Positive 3 3.7 4 Klebsiella sp. #1 Negative 3 3.5 6Klebsiella sp. #2 Negative 2 4.1 5 Klebsiella sp. #3 Negative 3 5.1 6 S.maltophilia Negative 2 2.8 4 Enterobacter sp. Negative 4 5.3 6Acinetobacter sp. Negative 4 5 6 E. Coli Negative 3 4.2 5 Group BStreptococci Positive 1 1.5 2 Mycobacterium Positive 7 9.2 10 Average2.77 3.82 4.77 SD 1.01 1.17 1.3

As can be seen in Table 1, this study showed that gNO at 200 ppm had acomplete bactericidal effect on all microorganisms tested. Withoutexception, every bacteria challenged with 200 ppm gNO had at least a 3log₁₀ reduction in CFU/mL. Furthermore, every test resulted in acomplete and total cell death of all bacteria. These results werecharacterized by a period of latency when it appeared that the bacteriawere unaffected by gNO exposure. The latent period was then followed byan abrupt death of all cells; gram negative and gram positive bacteria,antibiotic resistant bacterial strains, yeast and Mycobacteria all weresusceptible to 200 ppm gNO. It is noted that the two drug resistantbacteria strains were also susceptible to treatment with gNO at 200 ppm.

These results indicate to a significant difference in the lag period forMycobacteria compared to all other organisms. The lag period suggeststhat Mycobacteria may have a mechanism that protects the cell from thecytotoxicity of gNO for a longer period than other bacteria.

Example 2 Determination of Effective Antiviral Level of gNO

The efficacy of treating human influenza A with gNO has been studied.Two strains (H3N2 and H7N3) of the virus were studied and showed thattreating influenza virions or incubated cells with 160 ppm exogenous gNOreduced not only viral replication but also their infectivity in aMadin-Darby Canine Kidney (MDCK) cell model of infection. gNO has beendemonstrated as an effective anti-viral agent in both human Influenza Aand highly pathogenic avian influenza.

The viruses used for the following experiments were from freezer stockscontaining 1×10⁶ 1×10⁷ pfu's/ml.

A standard plaque assay was used for the study. Frozen stock solutionsof virions were diluted 1:10 in PBS and 3 ml were placed in each well ofsix well trays. The samples were either exposed to 160 ppm gNO ormedical air at 37° C. Following exposure 0.5 ml was inoculated ontoconfluent MDCK cells, grown in six well trays, and incubated at 37° C.for 1 hour. The inoculums were then removed and 1:1 mixture of 2× DMEMand agar, with 2% trypsin, was added to each well and then incubated at37° C. After 2 days the trays were fixed with 3.7% formaldehyde and theagar was removed from each well. The wells were then stained withcrystal violet revealing the plaques.

A standard plaque assay was used for a hemagglutination assay. Frozenstocks of virions were diluted 1:10 in PBS and 3 ml were placed in eachwell of six well trays. The samples were either exposed to 160-20,000ppm gNO or medical air at 37° C. For measure the effect of gNO on pH,when a large concentration of NO is added to saline the pH falls,therefore, a standard acid/base buffers were used to match the pH in thecontrol to that of the treated. Following exposure the samples werediluted 1:2 in round bottom 96 well trays. Guinea pig red blood cellswere added and agglutination was measured according to standardprocedures.

FIGS. 2A-C present plot of viral growth as a function of time measuredfor influenza A/victoria/H3N2 virions after exposure to nitric oxide 160ppm and 800 ppm continuously for 4 hours (FIG. 2A), the same virionsafter being exposed to one gNO dose over 30 minute as compared to three30 minute treatments Q4 h (FIG. 2B), and the effect of continuousexposure to gNO at a concentration of 160 ppm for 3 hours of the highlypathogenic Avian Influenza H7N3.

As can be seen in FIGS. 2A-C, gNO has been shown as capable of reducingthe infectivity of 2 strains of human influenza A/Victoria/H3N2 andHPAI/H7N2 viruses, and that the anti-viral effect of exposure to 160 ppmgNO is more evident in the intermittent form of exposure.

The efficacy of treating viral infection by respiratory syncytial virusby the methods presented herein was tested by exposure for 30 minutes ofhuman respiratory syncytial virus (rgRSV30) to a gas mixture containing160 ppm nitric oxide, using standard plaque assay as describedhereinabove.

FIGS. 3A-D present the data obtained in the experiment using tissueculture samples harboring human rgRSV30, coupled to a green fluorescentprotein, wherein the control experiment the samples were exposed to aambient air (data not shown), and the tested samples having a startingviral level of 2000 PFU (FIG. 3A), 1000 PFU (FIG. 3B) and 500 PFU (FIG.3C), were exposed to 160 ppm gNO for 30 minutes, whereas FIG. 3Dpresents a comparative bar plot comparing the control to test results.

As can be seen in FIGS. 3A-D, when the starting plaque-forming unit(PFU) of RSV was 2000 and 1000 PFU, a single exposure of 30 minutes to160 ppm gNO reduced the virus viability by a factor of bout 10, and at astarting level of 500 PFU, viral viability was substantially nullified.

Example 3 Administration of gNO to Healthy Human Subjects

Cohort:

10 healthy adult volunteer subjects (5 males, 5 females), aged 20 to 62years, were enrolled in the study after screening their medical history,a physical examination, pulmonary function tests and blood values.Exclusion criteria included individuals less than 19 years of age,pregnant females and unwilling to practice birth control during thestudy, diagnosed with pulmonary disease, epistaxis, hemoptysis,methemoglobinemia, organ transplant recipient or receiving antibiotictherapy.

Regimen and Post-Treatment:

After obtaining informed consent, treatment was initiated within 5 daysof enrollment. Subjects were housed in a hospital ward and received 160ppm gNO for 30 minutes every four hours (Q4 h), five times a day, forfive consecutive days by inhalation. Subjects returned for follow-upevaluations 3, 7 and 21 days after the final gNO administration. Subjectsafety was determined by monitoring vital signs, methemoglobin levels,lung function, blood chemistry, hematology, prothrombin time,inflammatory cytokine/chemokines levels and endothelial activation.These parameters were compared to baseline and at various time-pointsduring and after gNO administration.

Device:

Subjects were administered gNO through a modified disposable mouthpieceto maximize mixing. Inspiration was spontaneously initiated by thesubject from a conventional intermittent positive pressure breathingrespirator (Mark-7, Carefusion, USA) in fixed flow mode delivering 48liters per minute (LPM). Flows of gas were verified with a calibratedmass flow meter (TSI, USA). Gaseous nitric oxide (gNO, obtained atINOmax, Ikaria, USA) at a concentration of 800 ppm delivered at a flowof 12 LPM was titrated into a distal delivery port on the mouth piececonnected to the respirator during inspiratory phase only (pressureswitch). The Mark 7 respirator was supplied by an air/oxygen blender(Bird Sentry, Carefusion, USA) set to deliver 26% oxygen.

All components of the gNO delivery system were approved by theTherapeutic Product Directorate of Health Canada.

Monitoring of Chemicals and Physiological Parameters DuringAdministration:

The levels of gNO, NO₂, O₂ and methemoglobin were monitored during theadministration of gNO. The target gas mixture was 160 ppm gNO with anitrogen dioxide (NO₂) level of less than 5 ppm and an oxygen (O₂) levelranging from 21% to 25%. Inspiratory NO, NO₂ and O₂ levels werecontinuously monitored by sampling from the mouthpiece sample portlocated about 6 millimeters from the mouth of the subject with anAeroNOx (Pulmonox, AB, Canada) NO, NO₂ and O₂ electrochemical analyzer.Delivery safety was determined by the number of occasions that NO₂exceeded 5 ppm, gNO exceeding 10% variation and O₂ dropping below 20%during gNO administration. A commercially available noninvasive pulseoximeter (Rad 57, Masimo Corporation, USA) was used to measuresaturation levels at the periphery of methemoglobin (SpMet).

These parameters were measured continuously during every gNOadministration course and for 3.5 hours after the first treatment of theday. Daily serum samples were collected and frozen at −80° C. and theserum nitrite/nitrite level was measured using the Griess reagent.

Subjects underwent full pulmonary function tests (PFT), including lungdiffusing capacity (DLCO) by a trained technician utilizing a calibratedpulmonary function system (Jaeger MasterScreen, VIASYS Healthcare, USA)on screening and days 2, 8, 12 and 26. Spirometry test (Microloop byMicro Medical, England) was performed on days 1, 3 and 4. Effect of gNOon lung function and DLCO was determined by changes from baseline,treatment days and follow up days.

General medical examinations were performed by a pulmonary physician onscreening and on days 8, 12 and 26 to obtain oxygenation and vital signmeasurements. Abbreviated physical examination by a registered nurse wascarried out each day prior to initiation of treatments on days 1-5.Oxygenation was measured with a pulse oximeter (Rad 57, MasimoCorporation, USA) which was used according to manufacturer's guidelinesto measure functional oxygen saturation of arterial hemoglobin (SpO₂)and heart rate. These parameters were measured continuously during everygNO administration and for 3.5 hours after the first treatment of theday. Cardiovascular status was determined by monitoring heart rate,blood pressure, respiratory rate and temperature. Values were recordedprior to the start of each gNO administration, following a 5 minuterest. During treatments, vital signs (except temperature) were alsoperformed 15 minutes after the start of the treatment and at the end ofgNO administration and recorded. After the first treatment each day,vital signs were recorded at every 30 minutes until the start of thesecond gNO administration of the day.

Hematological assessment included a complete blood count anddifferentials (hemoglobin, hematocrit, red blood cell count, white bloodcell count, white blood cell differential, and platelet count) wereobtained in order to monitor blood chemistry, hematology andinflammation measurements. The blood chemistry profile included serumcreatinine, and liver function tests such as aspartate aminotransferase(AST) serum glutamic oxaloacetic transaminase (SGOT), alkalinephosphatase, and gamma-glutamyl transferase (GGT). The effect of gNO oncoagulation was determined by the prothrombin time (PT) and its derivedmeasures of prothrombin ratio (PR) and international normalized ratio(INR). Heparinized plasma was collected at baseline and on days 1, 2, 4,and 5 of gNO administration, and on follow-up days 3, 7 and 21 andfrozen at −80° C. Plasma cytokine levels were assessed using the humaninflammation cytokine bead array kit (BD Bioscience, Canada). Plasmalevels of angiopoietin Ang-1 and Ang-2 were determined by ELISA (R&DSystems, USA).

A total of 750 measurements of gNO were recorded during the study. Theaverage inspired gNO was 163.3 ppm (SD=4.0). The highest gNOconcentration recorded was 177 ppm. The highest NO₂ level recordedduring the treatments was 2.8 ppm (mean: 2.32; 95% confidence level:2.17-2.47 ppm) and none of the subjects experienced a NO₂ level higherthan 5 ppm. This was consistent with the performance specificationsprovided by the manufacturer of the apparatus of 1.56 ppm (SD=0.3). Ofthe 300 recorded oxygen values, the average oxygen level was 22.0%(SD=0.22%).

Data Analysis:

Descriptive statistical characteristics of the subjects prior to,during, and at the end of the study were tabulated and expressed asmean±standard deviation (SD). Differences in continuous variables(methemoglobin, serum nitrites/nitrates and SpO₂ levels) over the courseof the study were analyzed utilizing repeated measures analysis ofvariance. Categorical events (number of subjects with a particularadverse event) were determined by constructing 95% confidence limits fortheir incidence. Differences between continuous variables at twospecific times were evaluated with the paired t-test. Categorical eventssuch as clinical pulmonary function and lung diffusion changes, changesin serum inflammatory markers, hematology, clinical chemistry andincidence of adverse events were analyzed by constructing 95% confidencelimits for their incidence.

The data were analyzed using the unpaired Mann-Whitney test forcomparison between any two groups and ANOVA for repeated measures ofvariance. Baseline comparisons were analyzed by repeated measures ANOVAwith Bonferroni post test for parametric data, or Friedman test withDunn's post test for non-parametric data.

Data analysis and graphical presentation were done using a commercialstatistics package (Graphpad-Prism V 3.0, GraphPad Software Inc., USA).

Unless otherwise specified, p<0.05 indicated statistical significance.Results were represented by mean±SD from at least three independentmeasurements.

Results of Safety Studies:

Medical observation of adverse effects and general safety issues,concerning the repeated delivery of gNO at a concentration of 160 ppminto the airways of 10 healthy adult individuals, was effected bymonitoring excessive NO₂ levels, while maintaining acceptable arterialhemoglobin oxygen saturation (SpO₂). A total of 250 gNO administrationprocedures were conducted to 10 subjects during the study period. Alltreatments were well tolerated and no significant adverse events wereobserved. Three minor adverse events were reported: One subject reportedbruising of the arm from multiple attempts to successfully draw blood,while two other subjects reported a numbing sensation of the tongueduring gNO administration. This was resolved by instructing the subjectto relax and reposition the mouth piece.

During and after gNO administration, all vital signs remained withinnormal limits for age and with respect to baseline values. Specifically,there was no drop in blood pressure (which could potentially occur dueto the vasodilator effect of gNO administration) during or after gNOadministration. No sudden incidences of hypoxemia (less than 85% SpO₂)were observed during or after gNO administration. The lowest observedSpO₂ was 93%. SpO₂ levels over time decreased slightly between thepretreatment and post treatment but neither differed significantlystatistically nor clinically. ANOVA analysis ruled out that thisdecrease was associated with the five repeated exposures to gNO over thecourse of the same day.

FIGS. 4A-B present results of monitoring methemoglobin levels before,during and after inhalation of 160 ppm of gaseous nitric oxide by 10healthy human individuals, undergone 5 gNO administration courses daily,each lasting 30 minutes, for 5 consecutive days, while methemoglobinlevels were measured using a pulse oximeter, wherein FIG. 4A is a plotof methemoglobin levels by percents as a function of time as measuredbefore (time point 0), during 250 individual 30 minutes gNOadministration courses (time interval of 0 to 30 minutes), after thecourses (time interval of 30 to 60 minutes) and at 120 minutes, 180minutes and 240 minutes after gNO administration was discontinued, andFIG. 4B is a plot of methemoglobin levels by percents as a function oftime as measured at the beginning and end of 30 minutes gNOadministration courses given over the course of 5 days, and followed 8,12 and 26 days after gNO administration was discontinued.

As can be seen in FIG. 4A, all 930 recorded methemoglobin percent levels(SpMet) remained below the acceptable maximal level of 5%. The initialbaseline SpMet was 0.16 (SD=0.10) percent. The highest SpMet wasobserved at the end of the 30 minutes treatment and was 2.5% with anaverage increase of 0.9% (SD=0.08). SpMet increased as predicted byabout 1% between pretreatment and post treatment (p<0.001) and returnedto baseline after 3.5 hours prior to the next gNO administration.

As can be seen in FIG. 4B, ANOVA analysis ruled out that this increasewas associated with repeated treatments on the same day, as there was noaccumulative or lingering effect on SpMet after five daily treatmentsfor five consecutive days. Follow-up SpMet measurements on 3, 7 and 21days after the final exposure to gNO on day 5 did not show any residualincrease in SpMet.

Methemoglobin is reduced by an enzymatic reductase resultingtheoretically in an increase in blood nitrite/nitrate levels. However,no significant differences in serum nitrite/nitrate levels from baselinewere observed during the trial. One subject had significantly higherpeak nitrite and nitrate values (p<0.001) which was also slightlydifferent at baseline (p=0.038) compared to the other subjects.

There were no statistically, nor clinically significant changes in bloodcoagulation parameters, clinical chemistry and hematological parametersfrom baseline to completion of day 5. Although eosinophil cell numbersdecreased during the study (baseline 0.15 giga/L; SD=0.12; end of study:0.19 giga/L (SD=0.19), this difference was not significant (p=0.104). A1% increase in neutrophil cell numbers from a baseline value of zero to0.01 giga/L at the end of study was found, which also did not reachstatistical nor clinical significance (p=0.169).

FIGS. 5A-F present various results of monitoring pulmonary functionbefore, during and after inhalation of 160 ppm of gaseous nitric oxideby 10 healthy human individuals, wherein baseline values of pulmonaryfunction tests were obtained within 7 days prior to gNO administration,and values during gNO administration were obtained on day 2 of the5-days treatment and other data were obtained after the final gNOadministration on day 5 and on days 8, 12 and 26, wherein FIG. 5Apresents forced expiratory volume in 1 second in percents (FEV₁), FIG.5B presents maximum mid-expiratory flow (MMEF), FIG. 5C presents carbonmonoxide diffusing capacity (DLCO), FIG. 5D presents forced vitalcapacity (FVC), FIG. 5E presents total lung capacity (TLC) and FIG. 5Fpresents residual volume (RV), while all data are presented as means ofall ten subjects and absolute differences compared to baseline prior togNO administration, and statistical differences were assessed byMann-Whitney test.

As can be seen in FIGS. 5A-F, pulmonary function tests did not revealany abnormalities for any subjects during and after gNO administrationtreatments. Specifically, airflow as measured by FEV₁ and maximummid-expiratory flow (MMEF) did not differ from baseline during thecourse of the study. Other lung function measurements such as DLCO,forced vital capacity (FVC), total lung capacity (TLC) and residualvolume (RV) also did not change from baseline measurement.

To assess whether gNO inhalation may cause inflammation or endothelialactivation cytokines and the vascular endothelium activation factorsAng-1 and Ang-2 were quantified in peripheral plasma at baseline atvarious time points thereafter.

FIGS. 6A-F present blood levels of various cytokines before and afterinhalation of 160 ppm gaseous nitric oxide by 10 healthy humanindividuals, as measured from blood samples collected within 7 daysprior to gNO administration, each day during the treatment and 8, 12 and26 days thereafter, wherein FIG. 6A presents the plasma levels of tumornecrosis factor (TNF)α, interleukin (IL)-1ß data is presented in FIG.6B, IL-6 in FIG. 6C, IL-8 in FIG. 6D, IL-10 in FIG. 6E and IL-12p70 inFIG. 6F, as determined by a cytometric bead array while statisticaldifferences are compared by repeated measures ANOVA with Bonferroni posttest for parametric data (IL-6, IL-8, IL-10, IL-12p70), or Friedman testwith Dunn's post test for non-parametric data (TNF and IL-1b).

As can be seen in FIGS. 6A-F, cytokine levels of TNF, IL-6, IL-8, IL-10,IL-1b and IL-12p70 were unaffected by inhalation of gNO as compared tobaseline. Comparisons between baseline cytokine levels and levels ateach of the sampling time points for all 10 human participants resultedin no significant differences, compared by repeated measures ANOVA withBonferroni post test for parametric data, or Friedman test with Dunn'spost test for non-parametric data.

FIGS. 7A-C present plasma levels of angiopoietins Ang-1 and Ang-2 beforeand after inhalation of 160 ppm gaseous nitric oxide by 10 healthy humanindividuals, as measured in blood sample collected within 7 days priorto gNO inhalation, each day during gNO administration and 8, 12 and 26days thereafter, wherein plasma levels of Ang 1 are shown in FIG. 7A,Ang-2 in FIG. 7B, and Ang-2/Ang-1 ratios in FIG. 7C, as determined byusing a cytometric bead array while statistical differences wereassessed compared by Friedman test with Dunn's post test.

As can be seen in FIGS. 7A-C, Ang-2 and Ang-2/Ang-1 ratios were notaffected in this study. Outlier data in FIGS. 7A-C did not show anycorrelation with changes in any of the other parameters, and thusappears to be isolated findings of unknown significance.

Conclusions:

The safety of a treatment of human by inhalation of gNO at aconcentration of 160 ppm, has been demonstrated and presented herein. Ithas been shown herein that 160 ppm gNO can be safely delivered tohealthy human lungs in a pulsed manner for five consecutive days,showing no significant adverse events. All vital signs remained wellwithin acceptable clinical margins during and several days after gNOadministration at 160 ppm.

At least with regards to methemoglobin and NO₂ levels, the findingspresented herein are superior to findings obtained for continuousinhalation of 80 ppm gNO, which is the currently approved gNO dose forinhalational use in full term infants, presumably due to theintermittent dosing strategy utilized herein. While continuous deliveryof 80 ppm gNO has been reported to cause at least 5% increase of SpMetlevels, with 35% of the subjects exceeding 7%, the results presentedhereinabove (all 930 recorded SpMet levels) remained below 5%.

While the expected increase in methemoglobin levels during one treatmentcourse was estimated at 1%, the observed average rise of 0.9%methemoglobin for the ten individuals in a single treatment course wasconsistent with first order pharmacokinetics model estimates,considering the +1% absolute accuracy of the pulse oximeter. The studyestablished that 3.5 hour interim period allowed the methemoglobinconcentration to return to baseline, thereby allowing five daily cyclesfor five days without a significant clinical increase in methemoglobinconcentrations. Taken together, it has been shown herein thatintermittent gNO dosing strategy is safe for humans with regard ofmethemoglobin production and metabolic burden.

Similarly, the mean peak concentrations of NO₂ level shown hereinabove(2.8 ppm) is comparable with that observed during continuous delivery of80 ppm (2.6 ppm) of previous studies. The limitations of this and otherstudies with regard to gNO delivery are that the NO and NO₂ levels areonly known at the entry point into the subjects' respiratory tract andthe actual resulting levels of oxides of nitrogen in the lung areunknown. Despite this resilience to nitrosative stress, it may well beprudent in future studies to screen subjects for thiol and methemoglobinreductase deficiencies.

The study presented hereinabove also demonstrates that 160 ppm of gNO,delivered as outlined, impacts lung function only minimally, and acuteairway inflammation, measured by determining flow rates, was notdetectable. Possibly, potential deleterious airway reactivity could bemasked or prevented by the ameliorative smooth muscle relaxation that isknown to be exerted by gNO. In patients with pulmonary infection, highNO delivery might cause an increase in airway reactivity. However, thevasodilatory activity of NO may benefit the patient in addition to theantimicrobial activity of NO.

The delivery of 160 ppm NO to humans shown herein did not cause lungparenchymal injury, as measured by different lung function parameters.Likewise, plasma inflammatory cytokine levels, the earliest hostresponses to lung injury, and levels of eosinophils and neutrophilsremained constant during and days after gNO inhalation. In addition, thevascular endothelial activation factors Ang-1, Ang-2 and the Ang-2/Ang-1ratio were unaffected by gNO administration by inhalation.

Pulmonary function mechanics and inflammatory markers remained unchangedcompared to baseline values in measurements three days and 28 days posttreatment by gNO administration. While it cannot be exclude that somelonger term change may occur in lung function, the absence of any signof inflammation in the post treatment period shown hereinabove makesthis unlikely. If serum inflammatory markers may prove insensitive tomeasure acute or even chronic changes in the lungs, inflammatory markersfrom bronchioalveolar lavage (BAL) fluids could be sampled.

Example 4 Treatment of Bronchiolitis in Infants Using gNO

The following is a protocol for testing the efficacy and for treatinginfants suffering from viral bronchiolitis. Each patient is enrolled bythe research physician, and a parental informed consent signature isobtained in an official document. A detailed questionnaire is filled bythe physician and blood and nasopharyngeal samples for respiratoryviruses are obtained.

Indication and Prognosis:

Bronchiolitis is defined as an infection of the small airways. It isalso one of the most common manifestations of acute lower respiratorysystem infection in early infancy, and is the leading cause of globalchild mortality. In 2005 it has been estimated that 2.8 to 4.3 millionyoung children worldwide developed RSV-associated severe ALRInecessitating hospital admission. Hospitalization for bronchiolitis isexpensive with US hospital charges alone exceeding $1 billion in 2006.These charges in part reflect length of stay (LOS) in the hospital. Themean LOS for bronchiolitis in the United States is 3.3 days.

Bronchiolitis, which includes conditions associated with pathogenicviruses, bacteria, fungi or other irritants, is currently the mostcommon reason for pediatric hospital admission in the United States,accounting for almost 20% of all-cause infant hospitalizations. Viraletiology is the main cause and among the respiratory viruses,respiratory syncytial virus (RSV) is believed to be the most importantviral pathogen causing acute lower respiratory infection (ALRI) in youngchildren. It is estimated that 60,000 to 199,000 children younger than 5years die yearly from RSV-associated ALRI, with 99% of these deathsoccurring in developing countries. The disease is common mainly in thefirst year of life. The clinical signs and symptoms are consistent withhypoxia, difficulty in breathing, coryza, poor feeding, cough, wheezeand crepitations on auscultation and in some cases respiratory failure.

Current Treatment of Acute Bronchiolitis:

No specific treatment is available hitherto for the viral infection andonly supportive treatment such as oxygen and inhalations of hypertonicsaline or steroids with or without beta agonist drugs are being used todate.

Infants with hypoxemia are admitted for oxygen supplementation andsupportive treatment. The administration of oxygen and fluids are thecornerstone of the treatment of acute viral bronchiolitis. To date, allother interventions, including inhaled bronchodilators, corticosteroids,chest physiotherapy, anti-viral agents, and antibiotics are not provento be effective, and are not routinely recommended for the treatment ofacute viral bronchiolitis.

Disease Related Conditions:

Respiratory viruses are often responsible for the bronchiolitismanifestation, which is caused, exacerbated thereby or otherwiseassociated therewith. Among them the most common are respiratorysyncytial virus (RSV), rhinovirus, coronavirus, enterovirus, influenza Aand B, parainfluenza 1, 2 and 3, bocavirus, human metapneumovirus, SARSand adenovirus. However, other viruses and other pathogens often causeinfections that are manifested by bronchiolitis, and, in addition,bronchiolitis can occur as a result of conditions which are notassociated with any pathogen (e.g., cystic fibrosis complicationcomplications, cancer related immunosuppression, and various lungdisease, etc.).

Safety and Adverse Effects:

The observational objectives of the treatment with gNO of infants 2-12months old suffering from bronchiolitis include:

Assessment of clinical outcome;

Assessment of off-site parameters such as white blood cells counts; and

Assessment of respiratory viral load in the nasopharynx.

Any adverse event is documented and serious adverse events are addressedaccording to established protocols, the gNO treatment is ceased and theevent is reported to the relevant party.

Cohort Definition:

The cohort (case) definition fulfills the following criteria:

Infants 2-12 months old;

Diagnosed with bronchiolitis (respiratory distress with hypoxia);

No concomitant diseases such as pneumonia or otitis media;

No antibiotic treatment has been prescribed or needed;

Clinical score between 6-10 (see detailed description hereinbelow);

No underlying diseases; and

Documented informed parental consent.

An underlying disease is one such as genetics disorders or chronic lungdiseases.

Regimen:

Infants 2-12 months old which are admitted to the pediatric ward due tobronchiolitis are subjected to gNO treatment according to the regimendescribed in Example 3 hereinabove, namely, to inhalation of 163.3 ppm(SD of 4.0) gNO for 30 minutes, 5 times daily, for 5 consecutive days oruntil discharged, which occurs first.

The enrolled infants can be randomized in a 1:1 or 1:2 ratio to receivegNO with O₂ or Placebo (air) with O₂.

Clinical Score:

Table 3 presents the various criteria and scoring attributed to eachobservation, which is then summed up to obtain a clinical score.

TABLE 3 Use of <6 ≥6 SaO₂ accessory score months months Wheezing (roomair) muscle 0  40  30 None  ≥95% 1 41-55 31-45 End 92-94% + expirationaudible by stethoscope 2 56-70 46-60 Inspiration & 90-92% ++ expirationaudible by stethoscope 3 >70 >60 Audible  ≤89% +++ without stethoscope²

Clinical score is considered mild if <5; moderate at 6-7; and severe at11-12. If wheezes is not audible due to a minimal air entry, it isattributed a score of 3.

Monitored Parameters:

Clinical monitoring is carried our by recording a clinical score by aphysician twice daily. Oxygen saturation in room air is recorded threetimes a day.

Off-site laboratory monitoring is performed before and during treatmentand includes blood levels of methemoglobin, serum nitrites/nitrates,prothrombin, pro-inflammatory cytokines and 18 chemokines.

Table 4 presents the schedule for various protocol activities.

TABLE 4 Treatment day count Activity 0 1 2 3 4 5 6 10 30 Enrollment andinformed + consent Questionnaire + + gNO inhalation regimen + + + + + +Blood tests for WBC count, + + + + CRP, serum nitrites/nitrates andprothrombin, Blood levels of + + + + + + + + methemoglobinNasopharyngeal wash for + + respiratory viruses Blood levels forpro- + + + + inflammatory cytokines and chemokines Clinical scoreassessment + + + + + + + + +

Criteria for Efficacy:

The treatment is assessed by determining the rate of improvement of theclinical score, reduction of the length of hospitalization, rate ofimprovement of O₂ saturation, and rate of referral to a pediatricintensive care unit.

In addition, a reduction in viral load in the nasopharynx, determined byRT-PCR, is used to assess efficacy.

Example 5 Treatment of Bronchiolitis in Infants Using gNO-Clinical StudyProtocol

The following is an exemplary protocol for clinical studies based on themethods according to embodiments of the present invention, aimed attreatment of bronchiolitis in humans. Specifically, the topic of thestudy is a randomized double blind evaluation of efficacy, safety andtolerability of nitric oxide given intermittently via inhalation tosubjects with bronchiolitis.

The objectives of the study include the assessment of safety andtolerability of gNO intermittent inhalation treatment in 2-12 month oldinfants suffering from bronchiolitis. Other objectives include theassessment of efficacy of gNO intermittent inhalation treatment comparedwith standard treatment using O₂ in a group of similar subjects.

Equipment:

An improvised inhalation device is based on standard hospital equipmentand hospital oxygen source. For example, oxygen is supplied from themain hospital oxygen system via an oxygen blender, such as for example,Bird model 03800, followed by a hospital's oxygen mass flow meter. Theoxygen-rich air is monitored so as to reach a maximal finalconcentration of about 40% O₂. The blended air/oxygen is supplied to thesubject via a Y-shape connector attached next to a standard hospitalface mask such as for example, a Hospiltak mask by Unomedical Inc.

gNO flow, tapped from a tank containing 800 ppm nitric oxide in 99.999%pure N₂, supplied by an authorized gas provider in, for example, 50 or30 litter containers with 120 bar or 150 bar respectively, is adjustedby passing through a standard hospital's regulator, such as for exampleCareFusion™ model 400, and the hospital mass flow meter, such as aCareFusion™ model 77063.

NO accountability cannot be checked directly since several subjects mayreceive NO from the same container, and the net amount of NO used foreach inhalation is minimal comparing to the total container weight. Theamount of NO given per treatment is therefore evaluated based onpressure changes in the container (a rough evaluation).

The gNO flow is adjusted before each inhalation cycle based on the gNOconcentration detected in the subject's mask. After a fresh systemcalibration, the regulator and the mass flow meter are adjusted todeliver 160 ppm of gNO at 5 to 15 liters per minute. gNO is supplied tothe subject via the second arm of the Y shaped connector (specifiedabove) attached next to the face mask. Mask and tubing ports are used tomonitor continuously gNO and NO₂ concentrations and FiO₂ valuesdelivered to the subject.

Halitus (exhalation) is monitored by, for example, end-tidal CO₂(EtCO₂). EtCO₂ is monitored using standard equipment such as Microcap®Portable Capnography Monitor, Cat. # CS04179 by Oridion, Israel, withnasal prongs such as (Infant Neonate Cat. #008179 by Oridion, Israel.

Methemoglobin (SpMet) and oxygen saturation or dissolved oxygen (SpO₂)levels are monitored continuously using a dedicated monitor such as forexample RAD 57 by Masimo.

Cohort:

The population for the study is 44 children of 2-12 months old diagnosedwith bronchiolitis, whom required hospitalization (expected dropout rateis 10%). The population is split into two groups: Group 1, referred toas the treatment group, receives intermittent (5×30 minutes, a day)inhalation of 160 ppm gNO in addition to the standard treatment of O₂administration, for up to 5 days. Between gNO inhalations, the subjectscontinue to receive the standard inhalation treatment (O₂). Group 2,referred to as the control group, receives continuous inhalation of thestandard treatment (O₂).

Table 5 presents clinical score calculation, wherein a score lower than5 is mild; 6-10 is moderate, and 11-12 is severe, 11-12. In a score of2, if wheezes are not audible due to a minimal air entry, it isconsidered a score of 3.

TABLE 5 <6 ≥6 SaO₂ Accessory Score months months Wheezing (room air)muscle use 0  40  30 None  ≥95% None 1 41-55 31-45 End expiration92-94% + With Stethoscope 2 56-70 46-60 Insp. & Expiration 90-92% ++With stethoscope 3 >70 >60 Audible without  ≤89% +++ StethoscopeInclusion criteria are defined as male or female 2-12 months old,diagnosed with bronchiolitis at a clinical score of less than 10 (seebelow), and informed consent by parents/legal guardian.Exclusion criteria include: diagnosis of concomitant diseases such aspneumonia, urinary tract infection or otitis media; prematurity of lessthan 36 weeks gestational age; subject receiving RSV immunoglobulinprophylaxis; diagnosis of methemoglobinemia, chronic lung disease,immunodeficiency or heart disease; subject use of an investigationaldrug within 30 days before enrolment and not expected to participate ina new study within 30 days; history of frequent epistaxis of more than 1episode per month; significant hemoptysis within 30 days of more than 5ml of blood in one coughing episode or more than 30 ml of blood in a 24hour period; methemoglobin of more than 3% at screening; inability tofulfill the study design; presence of a condition or abnormality that inthe opinion of the investigator would compromise the safety of thesubject or the quality of the data; underlying diseases such as geneticdisorders, such as cystic fibrosis or Down syndrome or chronic lungdiseases such as bronchopulmonary dysplasia, primary ciliary diskynesia,bronchiolitis obliterans, hypotonia or congenital heart disease.

Regime, Route and Dosage Form of Administration:

The duration of the study for each subject is 30 (+5) days fromadmission to the department, through the treatment, including the followup period. All subjects show up for follow up visits on day 14 (+5 days)and are contacted on day 30 (+5 days) from day of admission.

Table 6 presents an exemplary study's assessment activity schedule,wherein (*) denotes treatment for 5 days or until subject discharge(whichever comes first), (**) denotes treatment on day 5 or at subjectdischarge (whichever comes first), in the morning, (***) denotestreatment by blinded study physician, and (****) denotes treatment incase the 5th treatment day is the 6th day from admission to the study.

TABLE 6 Day 1 - 1^(st) Study Day 14 Day 21 Day 30 Day 1− inhalation Day2 Day 3 Day 4 Day 5 Day **** 6 (+5) (+5) (+5) Admission + + +* +* +* +*+* Screening, Within 4 signing hours informed from consent and admissionEnrollment Randomization + Physical + +* +* +* +* +* + + exam***Clinical score + + +* +* +* +* +* + + assessment (twice a day morning +evening)*** Vital signs(once + + +* +* +* +* +* + + per shift) Study ++* +* +* +* +* (NO/control) treatment Blood tests: + + +* +* +* +* +* %methemoglobin; % oxyhemoglobin; Heart rate (every inhalation treatmentx5/24 hours)* NO, NO₂, + + +* +* +* +* +* FiO2 levels from the maskETCO2 level + + +* +* +* +* +* from the nasal prongs located in thesubject nostril Nasopharyngeal + +* +* +* +* +* + + and oropharyngealswabs for Streptococcus pneumoniae, Haemophilus influenzae andStaphylococcus aureus Nasopharyngeal + wash for respiratory viruses +PCR Questionnaire + + +  +  +  +  +  + + +/phone for all adverse effectsConcomitant + + +* +* +* +* +* + + + medication Document all + + +* +*+* +* +* + + + lab tests done for medical reasons

Table 7 presents the gNO administration and assessment schedule, wherein(*) denotes activity on the first inhalation on the first day oftreatment.

TABLE 7 Study Study Pre- Treatment During Study Treatment treatmentstart treatment end Time 30 60* 90* 120* 180* 210* 0 -min min min minmin min min Subject + eligibility NO cylinder + + pressure StandardO₂ + + + + + + + + + treatment NO treatment Start ongoing End (Group 1)OxyHem + + + Ongoing, + + + + + + MethHem record the measure -% valueobserved in case exceeding the approved range Heart Rate + 15 minafter + + + + + + the start of the treatment NO + NO₂, + + Ongoing, +FiO2, levels record the taken from value observed the mask in caseexceeding the approved range ETCO₂ level + + taken from the nasal prongslocated in the subject nostril all adverse + + + + + + + + + effectsConcomitant + + + + + + + + + medication

Treatment blindness is kept by separating between un-blinded teammembers giving the actual treatment and blinded team members, and byhiding the NO container/source and all study related equipment behind acurtain.

Group 1 (treatment group) receives the standard treatment (O₂) combinedwith the inhalation via face mask of 0.08% gaseous nitric oxide (gNO,800 ppm) administered for 30 minutes every four hours, keeping a minimumof 3 hours between the end of one gNO inhalation cycle and the beginningof the next cycle, five times a day for five consecutive days or until adecision to discontinue therapy. The maximal cumulative exposure tonitric oxide is estimate at 2,000 ppm hours.

Group 2 (control group) receives standard treatment of O₂ inhalationwith the identical equipment as used to administer gNO to members ofGroup 1.

The end of study treatment for both groups is assessed by a “blinded”study physician based on clinical assessment. Subject improvement maylead to a decision of subject discharge from the study.

Considering an expected dropout rate of approximately 10%, 44 subjectsare recruited, in order to have a sample size of at least 40 (20 pergroup) subjects who completed the study.

Study Endpoints:

Primary safety end points include determining the methemoglobin (MetHb)percentage associated with inhaled gNO, and determining adverse eventsassociated with inhaled gNO.

Primary tolerability end points include proportion (%) of subjects whomprematurely discontinued the study for any reason, and proportion (%) ofsubjects whom prematurely discontinued the study due to adverse effects.

Secondary efficacy end points include the comparison of the length ofhospital stay (LOS) in days of subjects 2-12 months old diagnosed withbronchiolitis which were treated with gNO and standard treatment versussubjects treated with standard treatment; the comparison of the rate ofclinical score improvement of subjects 2-12 months old diagnosed withbronchiolitis which were treated with gNO and standard treatment versussubjects treated with standard treatment; and the comparison of thelength of oxygen treatment in hours of subjects 2-12 months olddiagnosed with bronchiolitis whom been treated with gNO and standardtreatment versus subjects treated with standard treatment.

Observational end points include observation of the number of subjectswith MetHb level higher than about 5% at any time point; observation ofthe change in the mean neutrophil and eosinophil counts of subjects 2-12months old whom been treated with gNO for bronchiolitis versus subjectstreated with standard treatment, observation of the number of subjectswith study drug related bleeding at any time point; observation of thereduction of bacterial carriage in the nasopharynx of S. pneumoniae, H.influenzae, S. Aureus and the assessment of clinical outcome during 21days from admission to the study of subjects 2-12 months old treatedwith gNO for bronchiolitis; and the assessment of off-site parameterssuch as white blood cell counts in subjects 2-12 months old treated withgNO for bronchiolitis versus subjects treated with standard treatment.

Criteria for treatment end due to subject improvement are based on thesubject's improvement that leads to a decision of subject discharge fromthe hospital.

Criteria for early temporary treatment discontinuation include:

Blood methemoglobin more than 5%;NO₂ level measured near subject's mouth more than 5 ppm;SpO₂ during treatment more than 90%;ETCO₂ of more than 60 mmHg; andAdverse effects that are suspected to be NO related, according tophysician discretion.

In any event that a measured parameter exceeds the approved level, thecurrent study treatment inhalation is be stopped. A repeat level is thenmeasured 30 minutes later and the final measurement is recorded. Thenext inhalation starts according to study protocol.

Criteria for early permanent treatment discontinuation include:

A second episode of blood methemoglobin more than 5%; andA clinical score of more than 10.

A subject whose treatment was discontinued for any reason exceptvoluntary parent/legal guardian consent withdrawal, completes all studyassessment including the follow up visits.

Concomitant medication (i.e. antibiotics or steroids) given during thestudy are not be held as a reason for treatment early discontinuation.

Criteria for early study withdrawal include:

Subject's parent/legal guardian withdrew consent;Study management requested subject to be withdrawn;Investigator's discretion;Protocol violation/non-compliance;Loss to follow-up/failure to return;Adverse event or serious adverse event; andDeath; in which case the study is stopped for all cohort member formedical re-evaluation.

Treatment Procedures:

Day 1:

Up to 5 inhalations depending on time of admission.

Pretreatment includes monitoring and recording levels of oxyhemoglobin(%), methemoglobin (%), EtCO₂, FiO₂, NO and NO₂. A baseline for gas flowis established to match patient's minute ventilation (5-15 Lpm), and thegNO flow is validated to achieve 160 ppm in the inhalation mask, withfluctuating not exceeding 15 ppm. If gNO is fluctuating, baseline gasflow is increased to meet patient's minute ventilation and flow demands.At the end of the pretreatment stage the mask is placed on the subject'sface.

At treatment start the following parameters are recorded:

Start time and cylinder pressure;heart rate;Oxyhemoglobin (%) and methemoglobin (%); andFiO₂, NO and NO₂ levels.

During treatment the following parameters are monitored and recordedcontinuously:

Oxyhemoglobin (%) and methemoglobin (%);FiO₂, NO and NO₂ levels taken from the mask;Any form of adverse effects; andheart rate 15 min after the start of the treatment.

Treatment ends 30 minutes after the start of treatment, and thefollowing is recorded:

Stop treatment time and cylinder pressure;

Any form of adverse effects;

FiO₂, NO and NO₂ levels;Heart rate;Oxyhemoglobin (%) and methemoglobin (%) levels;Only after the first inhalation of the first day for both groups, thefollowing is recorded: Oxyhemoglobin (%), methemoglobin (%) and heartrate 60, 90, 120, 150, 180 and 210 minutes after the start of treatment;

Questionnaire including all adverse effects is completed by the studycoordinator and study physician, and vital signs are measured once pershift.

Days 2-5 (or Day 6):

The last day of treatment is the 6th day from admission.

On Day 5 (or Day 6, if the 5th treatment day ends on the 6th day fromadmission or discharge day/last day of study treatment) up to 5inhalations, according subject clinical status.

Once a day in morning physical examination is performed vital signs arerecorded (including temperature, pulse, respiratory rate, blood pressureetc.);

Assessment of clinical score by a blinded physician; and

Detection of bacteria by culture from nasal swab (Nasopharyngeal andoropharyngeal swabs for Streptococcus pneumoniae, Haemophilus influenzaeand Staphylococcus aureus).

On a routine basis questionnaire including all adverse effects iscompleted by the study coordinator and study physician, and the subjectis observed so as to meet inclusion and exclusion criteria.

Pretreatment, treatment start, during treatment and end of treatmentprocedures are conducted as in Day 1.

End of treatment assessments are made 2-4 hours after last inhalationtreatment, and include assess clinical score, vital signs by a blindedphysician, oxyhemoglobin (%) and methemoglobin (%), detection ofbacteria by culture from nasal swab.

Scheduled Follow Up Visits:

Days 14+5 and 21+5:

Questionnaire including any adverse effects is completed by the studyPhysician;Review and document concomitant medications;Physical examination by the study physician;Assess clinical score by a blinded physician;Perform detection of bacteria by culture from nasal swab;Record in subject study file any lab tests (i.e., blood tests and chestx-ray) if taken for clinical reasons.

Day 30+5:

Questionnaire including any adverse effects is completed by the studyphysician;Review and document concomitant medications.

Medical/Clinical Assessment:

Initial demography/medical history form is filled, and a physicalexamination is performed. A physical examination is performed by aphysician at the screening day and during follow up visits. Body systemswhich are examined grossly include general, skin, lymph nodes, head,eyes, ears, nose and throat, respiratory, cardiovascular,gastrointestinal, neurologic and muscoskeletal. New abnormal findingsare documented and followed by a physician at the next scheduled visit.

An abbreviated physical examination is performed as deemed necessary bythe investigators. In addition to vital signs, body systems to beexamined grossly. Vital signs measurements after resting for 5 minutes,including heart rate, blood pressure, respiration rate and temperature,are performed and recorded three times a day.

Oxygen saturation (SpO₂) is measured by pulse oximetry (using e.g., RAD57) during each treatment and recorded before, during and after NOtreatment. In any event that SpO₂ level during treatment is less thanabout 89%, the current study treatment inhalation is stopped. A repeatlevel is measured 30 minutes later and the final measurement should berecorded. The next inhalation starts according to study protocol.

Methemoglobin levels are measured non-invasively and continuously usinga pulse methemoglobinometer during treatment and recorded before, duringand after on Day 1 through Day 5. Any methemoglobin level of more thanabout 5% requires a repeat measurement 30 minutes later, and the finalmeasurement is recorded. The next inhalation starts according to studyprotocol.

End-tidal CO₂ (EtCO₂) is measured using, e.g., MicroCap Capnograph andrecorded before and after treatment on Day 1 through Day 5.

Information regarding occurrence of adverse effects or events isdocumented throughout the study and until 30 day subjects follow up iscomplete. Event duration (start and stop dates and times), severity,outcome, treatment and relation to study medication (causality) and ifthe event is regarded as a severe adverse event, is recorded in the casereport form. Adverse effect or events are monitored until day 30 followup visit/call.

Concomitant medication given during the study does not lead to studytreatment discontinuation. All concomitant medications and concurrenttherapies are documented throughout the study until day 30 follow upvisit/call. The following information is recorded: dose, route, unitfrequency of administration, and indication (if deemed relevant) foradministration of medication. The reason for administration ofconcomitant medications is considered as an adverse effect or eventunless it was scheduled prior to study start.

Any laboratory tests results received during subject's hospitalizationor study follow up are recorded in the subject file and used forobservational analysis.

Nasal wash for determination of viral shedding is collected in a sterilespecimen cup. Nasal swab (nasopharyngeal and oropharyngeal) fordetermination of bacteria (Streptococcus pneumoniae, Haemophilusinfluenzae and Staphylococcus aureus) is collected in a sterile specimencup.

Adverse Effects or Events:

Adverse events are recorded from the date of subject's signed informedconsent form and throughout the study, including the follow-up period.Adverse events should be reviewed and updated at each subsequent visitand during any phone contact with the subject. The intensity or severityof adverse event is characterized as mild if it is easily tolerated,moderate if it is sufficiently discomforting to interfere with dailyactivity, and severe if it prevents normal daily activities.

The causality of the adverse event is assessed as:

Unrelated when the adverse event is clearly and incontrovertibly due toextraneous causes (disease, environment, etc.);

Unlikely related if the adverse event meets at least two of thefollowing criteria: it does not follow a reasonable temporal sequencefrom study-drug administration; it could readily have been produced bythe subject's clinical state, environmental or toxic factors or othermodes of therapy administered to the subject; it does not follow a knownpattern of response to the study-drug, and does not reappear or worsenwhen the drug is re-administered;

Possibly related if the adverse event meets at least two of thefollowing criteria: it follows a reasonable temporal sequence fromstudy-drug administration; a causal relationship to the experimentaltreatment cannot necessarily be reasonably excluded and an alternativeexplanation (e.g., concomitant drug or concomitant disease) cannot bereasonably suggested as causing the SAE; and it follows a known patternof response to the study-drug;

Probably related if the adverse event meets at least three of thefollowing criteria: it follows a reasonable temporal sequence fromstudy-drug administration; it cannot be reasonably explained by theknown characteristics of the subject's clinical state, environmental ortoxic factors or other modes of therapy administered to the subject; itdisappears or decreases on cessation or reduction of the drug dose, andit follows a known pattern of response to the study-drug.

Potentially NO related adverse events are those which are associatedwith methemoglobinemia (% methemoglobin elevation) of more than 5%, andNO₂ elevation of more than 5 ppm.

Data Processing and Statistical Considerations:

For categorical variables summary tables are created, giving samplesize, absolute and relative frequency and 95% confidence interval forproportions by study group.

For continuous variables summary tables are provided, giving samplesize, arithmetic mean, standard deviation, coefficient of variation (ifappropriate), median, minimum and maximum, percentiles and 95%confidence interval by study group for means of variables.

Chi-square test or Fisher's Exact test are applied for testingdifference in proportions between the study groups.

Adverse events are coded according to coding dictionaries such asMedical Dictionary for Regulatory Activities (MedDRA version 14.0 orhigher) and presented in tables by System Organ Class (SOC) andPreferred Term (PT).

95% confidence interval (CI) is calculated for the proportion ofsubjects having adverse effects associated with inhaled gNO.

The Paired T-test or Signed rank test for two means are applied foranalyzing changes in continuous parameters within each study group.

The two-sample T-test or Non-parametric Wilcoxon-Mann-Whitney Rank sumtest for independent samples are applied for analyzing differences incontinuous parameters between the study groups.

All tests are two-tailed, and a p-value of 5% or less is consideredstatistically significant.

The data are analyzed using data processing software such as the SAS®version 9.1 (SAS Institute, Cary N.C.).

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention. To the extent thatsection headings are used, they should not be construed as necessarilylimiting.

1. A method of treating coronavirus in a patient in need of suchtreatment, the method comprising daily subjecting the patient tointermittent inhalation of gNO, wherein intermittent inhalationcomprises continuous inhalation of the gNO at a concentration of atleast 160 ppm for a first time period, followed by inhalation of no gNOfor a second time period; wherein the first time period ranges from 10to 45 minutes; wherein the second time period ranges from 3 to 5 hours;wherein during gNO administration NO₂ levels do not exceed 5 ppm, gNOconcentration variations do not exceed 10%, and FiO₂/O₂ levels do notdrop below 20%.
 2. The method of claim 1, wherein the patient issubjected to 3-6 cycles of intermittent inhalation of gNO per day. 3.The method of claim 2, wherein the patient is subjected to 3 cycles ofintermittent inhalation of gNO per day.
 4. The method of claim 2,wherein the patient is subjected to 5 cycles of intermittent inhalationof gNO per day.
 5. The method of claim 1, wherein the patient issubjected to intermittent inhalation for 3 to 7 days.
 6. The method ofclaim 1, wherein the first time period is about 30 minutes.
 7. Themethod of claim 1, wherein the second time period is about 3.5 hours. 8.The method of claim 1, further comprising monitoring, during andfollowing the subjecting, at least one on-site parameter selected fromthe group consisting of: a methemoglobin level (SpMet); an oxygensaturation level (SpO₂); an end tidal CO₂ level (ETCO₂); and a fractionof inspired oxygen level (FiO₂), and/or at least one off-site parameterselected from the group consisting of: a serum nitrite level (NO₂ ⁻); aserum nitrate level (NO₃ ⁻); and an inflammatory cytokine plasma level.9. The method of claim 8, comprising monitoring at least two of theparameters.
 10. The method of claim 8, comprising monitoring all of theparameters.
 11. The method of claim 8, wherein a change in the at leastone of the parameters following the subjecting is less than 2 acceptabledeviation units from a baseline.
 12. The method of claim 9, wherein achange in at least two of the parameters following the subjecting isless than 2 acceptable deviation units from a baseline.
 13. The methodof claim 10, wherein a change in all of the parameters following thesubjecting is less than 2 acceptable deviation units from a baseline.14. The method of claim 8, wherein a change in at least one of theon-site parameters following the subjecting is less than 2 acceptabledeviation units from a baseline.
 15. The method of claim 8, wherein achange in at least one of the off-site parameters following thesubjecting is less than 2 acceptable deviation units from a baseline.16. The method of claim 8, further comprising monitoring urine nitritelevel.
 17. The method of claim 16, wherein a change in the urine nitritelevel following the subjecting is less than 2 acceptable deviation unitsfrom a baseline.
 18. The method of claim 1, further comprisingmonitoring at least one off-site parameter selected from the groupconsisting of: a hematological marker; a vascular endothelial activationfactor; a coagulation parameter; a serum creatinine level; and a liverfunction marker.
 19. The method of claim 18, wherein a change in atleast one of the off-site parameters following the subjecting is lessthan 2 acceptable deviation units from a baseline.
 20. (canceled) 21.(canceled)
 22. The method of claim 1, further comprising monitoring atleast one on-site parameter selected from the group consisting of: avital sign; and a pulmonary function.
 23. The method of claim 22,wherein no deterioration is observed in the at least one parameterduring and following the subjecting.
 24. The method of claim 8, furthercomprising monitoring at least one on-site parameter selected from thegroup consisting of: a vital sign; and a pulmonary function.
 25. Themethod of claim 24, wherein no deterioration is observed in at the atleast one parameter during and following the subjecting.
 26. The methodof claim 1, wherein during the first time period, a concentration of O₂in the continuous inhalation ranges from 20% to 25%.
 27. The method ofclaim 1, wherein during the first time period, a fraction of inspiredoxygen level (FiO₂) in the continuous inhalation is greater than 21%.28. The method of claim 8, wherein the at least one parameter comprisesETCO₂ and during and following the subjecting, the ETCO₂ is less than 60mmHg.
 29. The method of claim 8, wherein the at least one parametercomprises SpMet and during and following the subjecting, the SpMet isincreased by less than 5%.
 30. The method of claim 8, wherein the atleast one parameter comprises SpO₂ and during the subjecting, a level ofthe SpO₂ is higher than 89%.
 31. The method of claim 9, wherein the atleast two parameters comprise serum nitrite/nitrate level and during andfollowing the subjecting, a level of the serum nitrite is less than 2.5micromole per liter and a level of the serum nitrate is less than 25micromole per liter, respectively.
 32. The method of claim 1, whereinduring the first time period, a fraction of inspired oxygen level (FiO₂)in the continuous inhalation is greater than 30%.